get rid of SSE quant_non_intra (which was broken, and abusing
program-wide SSE rounding flags which affected the ability to write other SSE routines). Totally rewrite MMX quant_non_intra so that it is 1) correct, and 2) faster than the SSE code was!
Authored by: trckjunky 2004-12-22
Parent: [r2551]
Child: [r2553]
