fix parser

Add capabilities to the parser ... these are just the parser/AST changes, with full implementation to be done in a future commit.
Add 'provenance', 'signature' to func defs.
Add 'where' to func defs.  TBD how to handle 'where' for class/interface.
Add 'parents' to interface/class defs.
Changed 'raises' to 'raise' in function definitions, to minimize new reserved wrods.
Turn off tests for representation equality (not needed because of Eq capability).