moving changes from java_rewriting_engine4 branch
fixing . to become .K or .Bag
change :>Constant :>Int back
change :>Constant :>Int back
change :>Constant :>Int back
fixing ambiguity
bring functionality from master branch
bring functionality from master branch
fixing bugs
fixing bugs
Merge pull request #38 from liyili2/java_rewrite_engine

Java rewrite engine