Dpkg::Conf: Document obsolete functions

This fixes a Pod::Coverage issue.

debian/changelog

@@ -103,6 +103,7 @@ dpkg (1.18.11) UNRELEASED; urgency=medium
       verify digests too. Prompted by Johannes Schauer <josch@debian.org>.
     - Document the behavior for consecutive calls to Dpkg perl module parse()
       methods. Prompted by Johannes Schauer <josch@debian.org>.
+    - Document obsolete functions in Dpkg::Conf.
   * Test suite:
     - Make test main function a TEST_ENTRY macro. This avoids confusing
       coverage programs, as the file that actually contains the main function

scripts/Dpkg/Conf.pm

@@ -85,8 +85,13 @@ sub get_options {
     return @{$self->{options}};
 }
 
-# These functions existed for a brief time, but do not mesh well with
-# repeated options.
+=item get()
+
+=item set()
+
+Obsolete functions, use get_options() instead. They will croak.
+
+=cut
 
 sub get {
     croak 'obsolete function, use get_options instead';