Added screenshot comparison in AutoTest (pspautotests).

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3382 4ab978e6-3352-0410-996c-0b42db0051c8
Small fixes in Vfpu instructions from pspautotests:
- VMOV: consumes PFXT prefix.
- better precision matching PSP in VSIN, VCOS, VASIN, VNRCP, VNSIN, VAVG, VROT
- improved NaN support in VH2F

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3383 4ab978e6-3352-0410-996c-0b42db0051c8