Fix geval numerical with matrix output.

Surpised that none of our unit tests caught this one. Numerical differentiation
of matrix valued functions simply errored due to a subscripted assignment
dimension mismatch. This commit also adds a test that would have alerted us to
the problem.
Merge pull request #157 from jacob-izr/master

Fixed instability in runLQR in UnderwaterAcrobot example - this time I think it works
Merge pull request #158 from avalenzu/fix-geval-matrix-output

Fix geval numerical with matrix output.
fix typo found by Hongkai
change add_mex to add_executable for ik c++ test
fix the problem of seg fault by changing add_mex to add_library in drakeQuatUtil. Also add robotnum in URDFRigidBodyManipulator
1. find some bugs in RigidBodyConstraint.cpp and inverseKinBackend.cpp
2. Add test for RigidBodyConstraint when time is not in the tspan
Forgot to delete an unused library
cleaner directory ref
set cMakelists the way I think they should be.  working on cmake
Remove the dependencies on MAT file in the C++ executables for IK test
Merge pull request #161 from hongkai-dai/master

Remove the dependencies on MAT file in the C++ executables for IK test
remove deprecated option for multipleShooting from trajectoryOptimization
fix taylorvar grads
added thrust to urdf model.  simple openloop animations look good.  lqr has problems, probably due to issue #165
added dircol stub.  it also fails, presumably due to #165.  added random obstacles and collision objects.  its fun to watch
added thrust to urdf model.  simple openloop animations look good.  lqr has problems, probably due to issue #165
added dircol stub.  it also fails, presumably due to #165.  added random obstacles and collision objects.  its fun to watch
TSRBM is only used to simulate.  added gravity method to RBM.  support Taylorvars in RigidBodyThrust
slider, since the traj opt w/ taylorvar takes *forever*