Chihiro WIP [Samuele Zannoli]
- Add NV2A vertex program disassembler
- Added two new debugger commands, grab_vprog <filename> to save the currently uploaded vertex program, and vprogdis <address, length>[<,type>] to disassemble a vertex program.
- Implemented alpha-test, blending, and logical per-fragment operations.  Improves many 2D displays in outr2.