Implementing limiting of input symbols to state machines
o Ensure minimal acceptable 'peekable' iterator has peek and sent
o Break out decide.execute method after it calls predicate
o Add optional 'limit=...' to state, capturing an int, str or predicate
  to use in determining ending source symbol for a state to transition.
o Pass deduced ending symbol through run/delegate
o Remove initialize, and move accept/process out of process/terminate
  try..finally; initialize is redudant with process
o Terminate before transitioning if we've reached our ending symbol
o Handle transitions where only exactly one decide target was given
o Test cpppo.remembering iterator, and new limit functionality
o Add dotdict.pop dotted name resolution; allows popping whole
  non-empy levels of the dotdict (del doesn't allow deleting such)
o Begin to add EtherNet/IP CIP parsing functionality