Added Moveit adapter package

This implements the Descartes `RobotModel` interface for MoveIt.  The PR includes some parts of PR #13, but not all.  Method implementations for `TrajectoryPt` are not included.  However, these methods will simply be wrappers around RobotModel calls when required.
I have a thought, and it may be induced by the delirium of slogging through boost function pointers and binding all day, but here goes (this is also inspired by something I saw in moveit, but I will have to dig it up some other time). Create a defaultAllIkSolver(Affine3d, vector<double>) implementation that contains this code. Then change this signature to getAllIK(Affine3d, vector<double>, boost::function<void (Affine3d, double)> = &defaultAllIkSolver). 
This would allow us to pass in a public function of an IKFast library as an alternative to random sampling. By default (passing no new function) this call would operate the same as here.