* modules/video_output/x11/xcommon.c, modules/video_output/directx/directx.c: when we invert the YV12 picture buffer chroma planes, we need to report a I420 chroma.

 modules/codec/ffmpeg/video_filter.c, modules/audio_filter/format.c, normvol.c: added Id svn keyword.

* src/video_output/vout_intf.c, modules/video_output/opengl.c: we do really need these, so please don't remove them again.

* modules/stream_out/transcode.c: use picture ring buffers to avoid leaks due to decoders not releasing pictures properly and to avoid uncessary mallocs.

* modules/gui/wxwindows/video.cpp: reverted change to re-use the video window as it doesn't work well on wxGTK.

* src/extras/libc.c: provide iconv facility in the core (vlc_iconv_open(), vlc_iconv(), vlc_iconv_close()).
* modules/misc/freetype.c, modules/codec/subsdec.c, modules/gui/skins2: use iconv from the core.

     and add callbacks if they already exist

Split out callback routines. 
Some cleanup. Still largely broken though.