aka : merge the big wx changes from branch

* modules/gui/wxwidgets/playlist.cpp: don't call treectrl->EnsureVisible() when updating a playlist item. That just makes navigation of the playlist unusable.

    - faad2, goom2k4, libpng, ffmpeg (modified gibalou's patch and moved it to a win32-file)

* modules/gui/wxwidgets/playlist.cpp: if too many items are queued to be added to the playlist then it is quicker to just rebuild the whole playlist instead of inserting items one by one (fixes huge slowdown when using shoutcast).

  When it is set to "true", the window is automatically resized
  when the vout size changes.

Todo:
	Fix FLAC
	SDL patch by Meuh

* modules/codec/libmpeg2.c: when AR is forced by input, assume it is based on width/height, not display_width/height (required for broken DVDs).

aspect ratio (e.g. 1280x800, 1920x1200)