65c02, etc support

[ksherlock]

This adds support for the WDC 65c02, Rockwell 65c02, and WDC 65c02s instruction sets. The default processor is still 6502 so there shouldn't be any effect on existing code [other than the __processor__ symbol). The instruction set is selected via -Pprocessor, where processor is 6502, 65C02, 65C02R or 65C02S (case insensitive). The __processor__ define is also set to the processor type. (eg, mif (strcmp(__processor__ , "6502") == 0) { ... } melse { ... }

The rockwell bit ops use 2 and 3 operands, eg, bbs 0,1,label or smb 0,7 instead of including the bit as part of the opcode (bbs0 1,label, smb0 7).