Revise German translation of MSGTR_Help.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36880 b3059339-0415-0410-9bf9-f77b7e298cf2
configure: ensure ffmpeg_a is either yes or no.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36881 b3059339-0415-0410-9bf9-f77b7e298cf2
configure: Fix PNG support for GUi check to always pass for external FFmpeg.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36882 b3059339-0415-0410-9bf9-f77b7e298cf2
configure: Avoid annoying error messages in case of external FFmpeg.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36883 b3059339-0415-0410-9bf9-f77b7e298cf2
configure: Revise some GUI related messages and output.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36884 b3059339-0415-0410-9bf9-f77b7e298cf2