Update libvorbis to 1.3.4, fixes issue #37
Update SDL to 2.0.3, fix libvorbis gitignore to prevent silly issue
Distclean kills SDL_image.spec (from the SDL image makefile) and it's rebuilt at make anyway. Shouldn't cause issues
And we should ignore that .spec file when we build it
Merge branch 'master' into dll-effect-emulation