Added test suite and tests for NFA parser and matcher (all passing)
Parser: added final critical piece: start anchor handling
tests: updated NFA tests to all have anchor (comments)

The previous schematics were that every expression has an implicit ^ at the start, so now that the parser works differently all the expressions needed to be updated to reflect this change.
Parser: removed some extra empty lines
Parser: removed unused type decl and added some comments (comments)

The comments are to pretty up the file a bit by explaining what is in that section