fmincon in NonlinearProgram uses user gradient now
in testIK, add check if snopt is not installed.
All the RigidBodyConstraint should check if the mex pointer of robot exists, before constructing the mex pointer of itself
inverseKin and inverseKinPointwise now uses ikoptions from the user in MATLAB
Merge pull request #452 from hongkai-dai/fix-testIKpointwise

Fix test ikpointwise