Complete development work for project two: improve support for input mapping

This is the part of the JEP requiring the most new coding. I'm fairly far advanced on one prototype, so the next step is for me to clean that up and to discuss the concept with others (again, most notably Leif and Kevin) to progress the prototype to a full implementation. Once the new input mapping implementation is in place, the next step is the long (and time consuming) process of manually moving all of our existing behavior code over to use this new API. This is definitely something that could be worked on by multiple people.

1) Continued development of InputMap API (including reviews, documentation, testing, integration): three weeks
2) Transliteration from old to new API: one - two weeks.

Total guestimate (with _no_ padding): five weeks.