* modules/codec/spudec/*: automatic cropping of fullscreen subpictures (most of them contain large transparent areas).
* src/video_output/vout_subpictures.c: more correct cropping (cropping coordinates are relative to the video size, not subpicture size).
* include/vlc_es.h, modules/video_filter/blend.c: use the i_entries member of video_palette_t.
* include/vlc_common.h: added SetWBE()/SetDWBE()/SetQWBE() facility.