Possibly fix #28?

[edmcman]

I haven't exhaustively tested, but it fixes the particular regex I was experiencing wrong results for, and a couple others I tried at random.

[qntm]

Going to have to reject this pull request, sorry! Although this fixes the specific case you mentioned, it introduces a few other test case failures, starting with test_star_advanced in fsm_test.py. You can run the whole suite using python -m pytest in the base directory of the project.

Also, if you are supplying a bug fix, please also add a test case which demonstrates the bug, like this:

def test_bug_28():
    # Defect in lego.to_fsm()
    assert not parse("(ab*)*").to_fsm().accepts("bb")