some harmless maintenance to the dictdoc shared test suite.
add child freq validation test.
some more harmless changes for the http test.
clean up and add docstring to protocol.dictdoc._fill
check_freq_dict => _check_freq_dict, moved validate_freq test outside.
added http validation tests.
added cascade as argument to model.complex.table to be directly passed to sqlalchemy.orm.relationship
lots of new validation tests that pass with a simpler _fill function.