Begin serious work on code generation
Updated cgtypes to reflect bittable.pdf
Temporary additions to cgtypes until merged with Standards.h
Merge branch 'master' into codegen
Get rid of trailing whitespace
Keep working on code generation.

    Moved code generation code out of giant switch
    Added a submarine
    Added cake
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
Replace raise with throw, use map.find properly in cg_lookup_label
CompilerException not CompilerError
Squash compile errors
Add Load, Store, Negate; mess with mask names in cgtypes
Add basic TRAPs, RET, and RTI
Added defines for trap vectors; added TRAP, RTI, OUT, PUTS, HALT, and RES

    Need to define helper functions