Previously Jacobians were stored by engines and accessed through engine
accessors (e.g getJacobianMatrixEntry); however, this resulted in
desynced jacobian states. We have changed to a pattern of Engine creates
a jacobian and returns it to the caller. The caller can then do what
they will with it. Because of this the getJacobianMatrixEntry method has
been removed.
BREAKING CHANGE:
- There is no longer any getJacobianMatrixEntry method on
DynamicEngine classes
- the generateJacobian method signature has changed to return a
NetworkJacobian object. Internally this uses an Eigen Sparse Matrix to
store its data.