WYC: added test case after interesting tutorial by Rustan Leino!!
WYC,WYCS: added test cases.
WyC: initial commit for modification to the way that requires and ensures is parsed.  This decision was heavily influenced by the Dafny tutorial I saw today given by Rustan Leino.
WYC: additional modifications to making writing loop invariants a little easier.
WyC: adding more test cases.
WyC: added another interesting test case.