Replace rotation functions with a simplified version adapted from vsfilter.
Replace rotation functions with a simplified version adapted from
vsfilter.

This (mostly) fixes http://bugzilla.mplayerhq.hu/show_bug.cgi?id=1394#c7

git-svn-id: 947b4ff483bb4cc5004120385d99e48ac0944466@28874 b3059339-0415-0410-9bf9-f77b7e298cf2

torque/libass,xbmc/libass,MrSmile/libass,vault/libass,blinkseb/libass,libass/libass,richardpl/libass,stps/libass,pigoz/libass-ct,vault/libass,tgoyne/libass,astiob/libass,grigorig/libass,rhlee/libass,richardpl/libass,grigorig/libass,tgoyne/libass,Akemi/libass,richardpl/libass,stps/libass,asimonov-im/libass,Akemi/libass,ShiftMediaProject/libass,sanyaade-g2g-repos/libass,stps/libass,rhlee/libass,Distrotech/libass,Distrotech/libass,mwgoldsmith/libass,sanyaade-g2g-repos/libass,astiob/libass,asimonov-im/libass,MrSmile/libass,tgoyne/libass,mwgoldsmith/libass,pigoz/libass-ct,Akemi/libass,xbmc/libass,pigoz/libass-ct,blinkseb/libass,libass/libass,torque/libass,mwgoldsmith/libass,ShiftMediaProject/libass,torque/libass,blinkseb/libass,rhlee/libass,Distrotech/libass,sanyaade-g2g-repos/libass