Refactor command type signatures.

Instead of giving an entire list of strings to the command functions, only
give the required amount of arguments.
Fix processCommands.
Use STM instead of MVar
derp
Made Value a GADT.
Merge branch 'master' of github.com:ZerglingRush/aclick into state

Conflicts:
	src/Command.hs
update perf tool and remove print statement
Add State to cabal file (and import it elsewhere)

Additionally, add back the printing of commands being done in Command.hs.
Makes debugging easier for now. Can remove later.
Add interactive client.
Be a bit nicer to users.