Changed parser test macros so that _parse_ok just checks whether the match succeeded and _parse_match actually checks the resulting parse tree

Revert "C++ tests set up. They probably don't compile; need to write iostream ops for prettyprinting and set up C++ build in scons." Should have branched it.

This reverts commit 6a29277d.

C++ tests set up. They probably don't compile; need to write iostream ops for prettyprinting and set up C++ build in scons.

h_ch's return type is uint, not bytes; fixed validate_test_ab accordingly, even though it worked before with the wrong union member name (probably because token is the first thing in the struct). Oh C, stay classy.