New Temporal Memory implementation

Progress on https://github.com/numenta/nupic/issues/1086.

Still working on end-to-end integration tests, but it looks like the basic functionality is working.

Please review: @scottpurdy 

@subutai If you get a chance, take a look at the generated documentation (you'll have to generate it yourself, at least until https://github.com/numenta/nupic/pull/1136 is merged), and see if it all makes sense to you at a high level. I've already shown you the design beforehand, so nothing should be too surprising there.
This seems a bit confusing since you are checking the length of self.segmentsForCell but updating self._segmentsForCell. Can you check `if cell in self._segmentsForCell` instead?