Further attempts to clean up underlying regex handling: WORK IN PROGRESS
One of the outstanding issues revolves around triggering the terminate()
method on state machine termination due to GeneratorExit (discarding
generator before completion), eg. due to reaching a non-transition in
a sub-machine.  Only if BOTH the containing dfa and the sub-machine are
in "terminal" state, does the terminate() run.  I think perhaps this should
only test if the sub-machine is terminal..
o README.org documentation changes
o Go back to completely eliminating non-terminal loopback "dead" states,
  and ensure all transitions to a "dead" state end up in a
  non-transition (explicitly or due to a wildcard transition).
o Fix a problem in parser.py; a transition in EPATH on \x11 wasn't
  correctly escaped for Python2/3 compatiblity (the only way to correctly
  type explicit b'...' elements in both versions is b'x'[0])