add missing include of stddef.h, as it's needed to use "ptrdiff_t"


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36789 b3059339-0415-0410-9bf9-f77b7e298cf2
Rename symbolic constants of GUI help message texts.

Create a kind of GUI namespace and don't add place or kind of
usage to the name unless it's advantageous.

This reduces the amount of definitions as well.

Arrange them alphabetically.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36790 b3059339-0415-0410-9bf9-f77b7e298cf2
Fix MSGTR_MPDEMUX_URL_StringAlreadyEscaped.

In r16882 the variable names seem to have mistakenly been used as
conversion specifications, resulting in a senseless output message.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36791 b3059339-0415-0410-9bf9-f77b7e298cf2
Revise MSGTR_MPDEMUX_URL_StringAlreadyEscaped.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36792 b3059339-0415-0410-9bf9-f77b7e298cf2
Improve testing of the help message header files.

Add a check for conversion specification mismatches in the translation.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36793 b3059339-0415-0410-9bf9-f77b7e298cf2