* modules/gui/skins/*: fix for msvc .dsp generation, replaced the BASIC_SKINS macro with the standard MODULE_NAME_IS_foo one and a couple of compilation fixes for msvc.
* msvc/vlc.dsw: added basic_skins and renamed mpeg_video into mpeg_video_old.
* modules/codec/mpeg_video/parser.c: fixed segfault when idct/motion modules can't be loaded.