contract monad as in paper
fix of monadic contract bugs
merge
Merge branch 'master' of github.com:HIPERFIT/contracts
Instances for Rexp literals

The usual Num and Fractional instance, and smart constructors.
Also some code for Bools, but commented out.
make API constructors a bit smart
nicer interface
monad fix
merge (conflict with new API)
Merge branch 'master' into extrinsic

Conflicts:
	Coq/Extraction/ContractExtracted.hs