Apply adub's lut2 patch that makes it work properly

git-svn-id: http://vapoursynth.googlecode.com/svn/trunk@478 f9120d27-2007-6f97-8312-0f4ebfa7710f
Fix format record leak when a core is freed
Fix windows compilation of adub's patch

git-svn-id: http://vapoursynth.googlecode.com/svn/trunk@479 f9120d27-2007-6f97-8312-0f4ebfa7710f
Replace gotos with ifs

git-svn-id: http://vapoursynth.googlecode.com/svn/trunk@480 f9120d27-2007-6f97-8312-0f4ebfa7710f