Make initial type declarations for memory and instructions
Add operator decoding
Add operand decoding.

Decoding literals doesn't work yet, since the
spec isn't clear, and I don't have internet at
the moment.
Support literal operands and code cleanup
Clean up code
Start work on Memory.hs.

I don't know what I'm doing.
Implementing load and store for memory
Add lots of non-working code.
Oh my god. Memory.hs works I think.
Changed rank2types to rankNtypes, added simple test for emulator monad