doc: Update Doxygen configuration from version 1.8.4

This gets rid of some warnings due to deprecated options.

doc/Doxyfile.in

@@ -1,8 +1,10 @@
-# Doxyfile 1.8.3.1
+# Doxyfile 1.8.4
 
 # This file describes the settings to be used by the documentation system
 # doxygen (www.doxygen.org) for a project.
 #
+# All text after a double hash (##) is considered a comment and is placed
+# in front of the TAG it is preceding .
 # All text after a hash (#) is considered a comment and will be ignored.
 # The format is:
 #       TAG = value [value, ...]
@@ -70,9 +72,9 @@ CREATE_SUBDIRS         = NO
 # Afrikaans, Arabic, Brazilian, Catalan, Chinese, Chinese-Traditional,
 # Croatian, Czech, Danish, Dutch, Esperanto, Farsi, Finnish, French, German,
 # Greek, Hungarian, Italian, Japanese, Japanese-en (Japanese with English
-# messages), Korean, Korean-en, Lithuanian, Norwegian, Macedonian, Persian,
-# Polish, Portuguese, Romanian, Russian, Serbian, Serbian-Cyrillic, Slovak,
-# Slovene, Spanish, Swedish, Ukrainian, and Vietnamese.
+# messages), Korean, Korean-en, Latvian, Lithuanian, Norwegian, Macedonian,
+# Persian, Polish, Portuguese, Romanian, Russian, Serbian, Serbian-Cyrillic,
+# Slovak, Slovene, Spanish, Swedish, Ukrainian, and Vietnamese.
 
 OUTPUT_LANGUAGE        = English
 
@@ -252,10 +254,10 @@ EXTENSION_MAPPING      = l=C
 
 MARKDOWN_SUPPORT       = YES
 
-# When enabled doxygen tries to link words that correspond to documented classes,
-# or namespaces to their corresponding documentation. Such a link can be
-# prevented in individual cases by by putting a % sign in front of the word or
-# globally by setting AUTOLINK_SUPPORT to NO.
+# When enabled doxygen tries to link words that correspond to documented
+# classes, or namespaces to their corresponding documentation. Such a link can
+# be prevented in individual cases by by putting a % sign in front of the word
+# or globally by setting AUTOLINK_SUPPORT to NO.
 
 AUTOLINK_SUPPORT       = YES
 
@@ -311,11 +313,11 @@ SUBGROUPING            = YES
 INLINE_GROUPED_CLASSES = NO
 
 # When the INLINE_SIMPLE_STRUCTS tag is set to YES, structs, classes, and
-# unions with only public data fields will be shown inline in the documentation
-# of the scope in which they are defined (i.e. file, namespace, or group
-# documentation), provided this scope is documented. If set to NO (the default),
-# structs, classes, and unions are shown on a separate page (for HTML and Man
-# pages) or section (for LaTeX and RTF).
+# unions with only public data fields or simple typedef fields will be shown
+# inline in the documentation of the scope in which they are defined (i.e. file,
+# namespace, or group documentation), provided this scope is documented. If set
+# to NO (the default), structs, classes, and unions are shown on a separate
+# page (for HTML and Man pages) or section (for LaTeX and RTF).
 
 INLINE_SIMPLE_STRUCTS  = NO
 
@@ -329,30 +331,14 @@ INLINE_SIMPLE_STRUCTS  = NO
 
 TYPEDEF_HIDES_STRUCT   = NO
 
-# The SYMBOL_CACHE_SIZE determines the size of the internal cache use to
-# determine which symbols to keep in memory and which to flush to disk.
-# When the cache is full, less often used symbols will be written to disk.
-# For small to medium size projects (<1000 input files) the default value is
-# probably good enough. For larger projects a too small cache size can cause
-# doxygen to be busy swapping symbols to and from disk most of the time
-# causing a significant performance penalty.
-# If the system has enough physical memory increasing the cache will improve the
-# performance by keeping more symbols in memory. Note that the value works on
-# a logarithmic scale so increasing the size by one will roughly double the
-# memory usage. The cache size is given by this formula:
-# 2^(16+SYMBOL_CACHE_SIZE). The valid range is 0..9, the default is 0,
-# corresponding to a cache size of 2^16 = 65536 symbols.
-
-SYMBOL_CACHE_SIZE      = 0
-
-# Similar to the SYMBOL_CACHE_SIZE the size of the symbol lookup cache can be
-# set using LOOKUP_CACHE_SIZE. This cache is used to resolve symbols given
-# their name and scope. Since this can be an expensive process and often the
-# same symbol appear multiple times in the code, doxygen keeps a cache of
-# pre-resolved symbols. If the cache is too small doxygen will become slower.
-# If the cache is too large, memory is wasted. The cache size is given by this
-# formula: 2^(16+LOOKUP_CACHE_SIZE). The valid range is 0..9, the default is 0,
-# corresponding to a cache size of 2^16 = 65536 symbols.
+# The size of the symbol lookup cache can be set using LOOKUP_CACHE_SIZE. This
+# cache is used to resolve symbols given their name and scope. Since this can
+# be an expensive process and often the same symbol appear multiple times in
+# the code, doxygen keeps a cache of pre-resolved symbols. If the cache is too
+# small doxygen will become slower. If the cache is too large, memory is wasted.
+# The cache size is given by this formula: 2^(16+LOOKUP_CACHE_SIZE). The valid
+# range is 0..9, the default is 0, corresponding to a cache size of 2^16 = 65536
+# symbols.
 
 LOOKUP_CACHE_SIZE      = 0
 
@@ -363,7 +349,7 @@ LOOKUP_CACHE_SIZE      = 0
 # If the EXTRACT_ALL tag is set to YES doxygen will assume all entities in
 # documentation are documented, even if no documentation was available.
 # Private class members and static file members will be hidden unless
-# the EXTRACT_PRIVATE and EXTRACT_STATIC tags are set to YES
+# the EXTRACT_PRIVATE respectively EXTRACT_STATIC tags are set to YES
 
 EXTRACT_ALL            = YES
 
@@ -761,8 +747,10 @@ IMAGE_PATH             =
 # is the value of the INPUT_FILTER tag, and <input-file> is the name of an
 # input file. Doxygen will then use the output that the filter program writes
 # to standard output.
-# If FILTER_PATTERNS is specified, this tag will be
-# ignored.
+# If FILTER_PATTERNS is specified, this tag will be ignored.
+# Note that the filter must not add or remove lines; it is applied before the
+# code is scanned, but not when the output code is generated. If lines are added
+# or removed, the anchors will not be placed correctly.
 
 INPUT_FILTER           =
 
@@ -792,9 +780,9 @@ FILTER_SOURCE_FILES    = NO
 FILTER_SOURCE_PATTERNS =
 
 # If the USE_MD_FILE_AS_MAINPAGE tag refers to the name of a markdown file that
-# is part of the input, its contents will be placed on the main page (index.html).
-# This can be useful if you have a project on for instance GitHub and want reuse
-# the introduction page also for the doxygen output.
+# is part of the input, its contents will be placed on the main page
+# (index.html). This can be useful if you have a project on for instance GitHub
+# and want reuse the introduction page also for the doxygen output.
 
 USE_MDFILE_AS_MAINPAGE =
 
@@ -939,7 +927,7 @@ HTML_EXTRA_STYLESHEET  =
 # The HTML_EXTRA_FILES tag can be used to specify one or more extra images or
 # other source files which should be copied to the HTML output directory. Note
 # that these files will be copied to the base HTML output directory. Use the
-# $relpath$ marker in the HTML_HEADER and/or HTML_FOOTER files to load these
+# $relpath^ marker in the HTML_HEADER and/or HTML_FOOTER files to load these
 # files. In the HTML_STYLESHEET file, use the file name only. Also note that
 # the files will be copied as-is; there are no commands or markers available.
 
@@ -1208,7 +1196,7 @@ FORMULA_TRANSPARENT    = YES
 USE_MATHJAX            = NO
 
 # When MathJax is enabled you can set the default output format to be used for
-# thA MathJax output. Supported types are HTML-CSS, NativeMML (i.e. MathML) and
+# the MathJax output. Supported types are HTML-CSS, NativeMML (i.e. MathML) and
 # SVG. The default value is HTML-CSS, which is slower, but has the best
 # compatibility.
 
@@ -1231,6 +1219,11 @@ MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
 
 MATHJAX_EXTENSIONS     =
 
+# The MATHJAX_CODEFILE tag can be used to specify a file with javascript
+# pieces of code that will be used on startup of the MathJax code.
+
+MATHJAX_CODEFILE       =
+
 # When the SEARCHENGINE tag is enabled doxygen will generate a search box
 # for the HTML output. The underlying search engine uses javascript
 # and DHTML and should work on any modern browser. Note that when using
@@ -1256,8 +1249,8 @@ SERVER_BASED_SEARCH    = NO
 # which needs to be processed by an external indexer. Doxygen will invoke an
 # external search engine pointed to by the SEARCHENGINE_URL option to obtain
 # the search results. Doxygen ships with an example indexer (doxyindexer) and
-# search engine (doxysearch.cgi) which are based on the open source search engine
-# library Xapian. See the manual for configuration details.
+# search engine (doxysearch.cgi) which are based on the open source search
+# engine library Xapian. See the manual for configuration details.
 
 EXTERNAL_SEARCH        = NO
 
@@ -1328,7 +1321,7 @@ COMPACT_LATEX          = NO
 
 # The PAPER_TYPE tag can be used to set the paper type that is used
 # by the printer. Possible values are: a4, letter, legal and
-# executive. If left blank a4wide will be used.
+# executive. If left blank a4 will be used.
 
 PAPER_TYPE             = a4wide
 
@@ -1351,6 +1344,13 @@ LATEX_HEADER           =
 
 LATEX_FOOTER           =
 
+# The LATEX_EXTRA_FILES tag can be used to specify one or more extra images
+# or other source files which should be copied to the LaTeX output directory.
+# Note that the files will be copied as-is; there are no commands or markers
+# available.
+
+LATEX_EXTRA_FILES      =
+
 # If the PDF_HYPERLINKS tag is set to YES, the LaTeX that is generated
 # is prepared for conversion to pdf (using ps2pdf). The pdf file will
 # contain links (just like the HTML output) instead of page references
@@ -1495,6 +1495,21 @@ XML_DTD                =
 
 XML_PROGRAMLISTING     = YES
 
+#---------------------------------------------------------------------------
+# configuration options related to the DOCBOOK output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_DOCBOOK tag is set to YES Doxygen will generate DOCBOOK files
+# that can be used to generate PDF.
+
+GENERATE_DOCBOOK       = NO
+
+# The DOCBOOK_OUTPUT tag is used to specify where the DOCBOOK pages will be put.
+# If a relative path is entered the value of OUTPUT_DIRECTORY will be put in
+# front of it. If left blank docbook will be used as the default path.
+
+DOCBOOK_OUTPUT         = docbook
+
 #---------------------------------------------------------------------------
 # configuration options for the AutoGen Definitions output
 #---------------------------------------------------------------------------
@@ -1644,6 +1659,12 @@ ALLEXTERNALS           = NO
 
 EXTERNAL_GROUPS        = YES
 
+# If the EXTERNAL_PAGES tag is set to YES all external pages will be listed
+# in the related pages index. If set to NO, only the current project's
+# pages will be listed.
+
+EXTERNAL_PAGES         = YES
+
 # The PERL_PATH should be the absolute path and name of the perl script
 # interpreter (i.e. the result of `which perl').
 
@@ -1740,7 +1761,7 @@ UML_LOOK               = NO
 # the class node. If there are many fields or methods and many nodes the
 # graph may become too big to be useful. The UML_LIMIT_NUM_FIELDS
 # threshold limits the number of items for each type to make the size more
-# managable. Set this to 0 for no limit. Note that the threshold may be
+# manageable. Set this to 0 for no limit. Note that the threshold may be
 # exceeded by 50% before the limit is enforced.
 
 UML_LIMIT_NUM_FIELDS   = 10