SDL_config.h is no longer in CVS.  Instead, configure will generate it for
systems that use configure, and we always copy SDL_config.h.default to
SDL_config.h before generating a snapshot or release archive.

Also fixed a couple of uninstall issues.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401610