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
Untested implementation of compiler

    Added:
        Two-pass kludge to calculate label locations
        Traps

    Known Issues:
        - Completely untested (Seriously! This hasn't been tested at all!)
        - No support for PUSH/POP
        - No support for IN, GETC traps
        - No location information provided
        - Labels positions are calculated using a super ugly horrible kludge
            (the code generator actually does everything except I/O twice)
        - There is no working frontend
        - No runtime easter eggs are present
        - Needs a better cake
        - Needs documentation
        - I'm hungry
Merge branch 'codegen' into New-Standards