Don't build the nacl branch just yet
Remove incorrect client-side definition of sv_cheats
Add SSE optimized implementation of vertex skinning

This is a 40%+ speed increase over the compiler's scalar SSE code
Remove SSEVEC3_T

This doesn't do anything but change the size of the vec3_t typedef, thereby introducing some compiler warnings and probably some subtle bugs as well
Fix erroneous use of MatrixIdentity on bone matrices
Merge branch 'master' into ioq3_sound
Fix opus file include locations