Added add/sub/div/mul operations.

These all work the same:

    OPERATION dest-reg src-reg1 src-reg2
Add support for mathematical operations.

These all work the same:

    (add|sub|mul|div) #dest-reg, #src1-reg, #src2-reg
Misc updating.
Added sample addition-program.
Ignore 'compiled' programs
Ignore 'compiled' programs