render.c: RV16 now works great - uses all colors, but no transparancy.

render.c: RV16 now works great - uses all colors, but no transparancy.
Started RV32 and- has bugs. (It'd be nice if something in rendering
worked the first time without a hassle).

Modules.am, pixmap.h, subtitle.h: Some of the pixel stuff has been
moved here.

cvd.c: remove option duplicated with ogt.c Probably should be hoisted more
to a main routine. Perhaps if spudec is folded in.