More interpreter entry point fixes and added some native functions
Some more semantics changes
Temporary workaround for Int(i) actually being Int(s) in incoming ctrees
Workaround premise merging incorrect for deep list matching in conclusion
Add support for AnnoSDef
Properly handle AnnoDef-s
Interpreter entry point with support for loading multiple ctrees.
Wrap the interpreter in a nice stateful interface
Extend interface of StrategoCoreInterpreter
Add test harness and test data