updating wingeron urdf colors and forest geometry.  don't need separate URDF for displaying collision geometry anymore.
Fix #95.

Uninitialized `kinsol` as argument to `collisionDetect` was causing a crash if
the test failed. Replaced `kinsol` with `q0`.
Merge pull request #96 from avalenzu/collision-minor-changes

Fix #95.
Change default terrain to no-terrain for RBM
Remove `options.terrain = []` from unit tests
Set `RigidBodyFlatTerrain` in examples.
Create a common parent class NonlinearProgramWKinsol class for InverseKin and InverseKinTraj. Should be easier to write code for dynamic planning
change the test criteria in testIK. Now I only check if the constraints are satisfied, but do not require that the solution from inverseKin MATLAB/C++ and InverseKin to be the same.
1.fix a bug in InverseKinTraj when adding the QuasiStaticConstraint
2.change the test file for inverseKinTraj. Now it checks if each constraint is satisfied.
remove the most of the test on additional time samples for inverseKinTraj. That part of the code should be reformulated, to take Russ's suggestion on parameterizing qdot as decision variables so as to make the gradient sparse
remove the randomness in testIKtraj to assure the test should aways succeed without worring about poor initial seed.
Merge pull request #98 from avalenzu/options-terrain

Options terrain
Merge pull request #99 from hongkai-dai/fixIKtest

Fix IK test
fix "unknown options" errors from Andres commit changing default display options.
fix atlas unit test (forgot to add terrain)
fix from ani for obstacle gradients.
Load meshes in `URDFRigidBodyManipulator`

Also fixes handling of collision elements so that the collision elements of
links with no "default" collision group are still parsed. Adds
`testURDFcollision` to check that `collisionDetect` returns the same
information for `RigidBodyManipulator` and `URDFRigidBodyManipulator`. Note,
the order of points returned, as well as the body indices are *not* the same
between these two classes. However, all the same collision pairs are checked.
Remove commented-out warnings
Merge pull request #101 from avalenzu/fix-URDFRigidBodyManipulator-warnings

Load meshes in `URDFRigidBodyManipulator`
add a CoMMatchConstraint to be used in CoMPlanning