Task space feature

This PR continues PR #210 but with the source moved into the simbody/simbody repo from chrisdembia/simbody. (via short-lived PR #237). This is so Chris and I can work on it together and with osrf.

cc/ @chrisdembia @hsu @scpeters 
This file should be removed for now. Otherwise, people might think the test does something. I did start working on a test case, but I have been neglecting it.