Added some more macros to cgtypes.h

    Removed aa_mode_t enum
    Added ROUNDVAL and ROUNDUP macros
Replace almost all enums with defines

    Keep extend_t enum
    Delete opcode_t enum
    Include Standards.h in codegen.cpp
Remove extraneous typedef
Fix defines for BR_CC_condition

    BR_CC_POS was used to mean "position" and "positive"
Add cg_branch for branch instructions

    - Declared a couple of new functions in codegen.h
    - Replaced calls to cg_write_uword to cg_write_instruction for writing
      instructions.
    - Rearranged function declarations in codegen.h to reflect
Refactor: register number generation; truncated number generation;
Add cg_jump, cg_jsr, cg_lookup_label, cg_pc_offset
Merge branch 'master' into codegen
Merge branch 'codegen' into New-Standards