implements an active set method for LCP time-stepping using the fastQP algorithm
better comments around reduced LCP logic
made data property public in SharedDataHandle
fix copy/paste bug
fixed contactSensorTest. disabled pathlcp warm starting since it is causing problems
fixed a bug and a corner case caught by unit tests
not using bullet to make these tests more reliable
fixed bug of carring over previous LCP solutions. turned bullet back on in multiRobotTest
bump position control gradients tolerance so it fails less frequently
revert tolerance increase in testPositionControlGradients and fix numerical gradient bug by using only the path solver
removes hidden state (caused by reuse of previous solutions) from TSRBM.solveLCP(). reverting changes to testPositionControlGradients.
disable bullet in constactSensorTest (and re-enable fastQP) because bad normals were causing the test to fail
Merge pull request #623 from kuindersma/fastLCP

active-set LCP