Finish basic implementations of State, Domain, and StateCollection.  Still unnecessarily complicated.
FSAStrategy has basic functionality working now.  A lot of execution code has been deleted instead of moved, for now.  Still needs a lot of cleaning-up, re-enabling of old functionality, and documentation.
give Region objects a nice __repr__
Switch states to use dicts as internal storage instead of sets, and to prefer
storing multivalent propositions as evaluated high-level values instead of subproposition
values, in order to make things more intuitive and possibly faster (at least in
the case of an explicit state strategy).   Also commented a
lot and added in a bunch of error checking (which was made easier by the
aforementioned changes).  Still a work in progress.
added execution of strategy as an extension now (can be changed later)
removed all direct access to variables in the strategy object
full modification for adapting strategy.py into execute.py and executeStrategy.py