dpkg-parsechangelog(1): precise that --all overrides the other options

debian/changelog

@@ -12,6 +12,8 @@ dpkg (1.15.6.2) UNRELEASED; urgency=low
     page.
   * Let dpkg-source read options from debian/source/local-options as well but
     do not include that file in the generated source package.
+  * Improve explanation of --all option in dpkg-parsechangelog(1). Thanks to
+    Jari Aalto. Closes: #575706
 
   [ Updated dpkg translations ]
   * German (Sven Joachim).

man/dpkg-parsechangelog.1

@@ -103,7 +103,8 @@ change the starting point for \-\-count, counted from the top
 (or the tail if \fInumber\fP is lower than 0).
 .TP
 .B \-\-all
-include all changes.
+include all changes. Note: other options have no effect when this is in
+use.
 .
 .SH CAVEATS
 All \fBParser Options\fP except for \-v are only supported in