Improved name tracking and lookup
don't change name if it's the same as the one we already have
inform the BodyNode of its Skeleton when it gets added
returning NULL if requesting an out of bounds index
comment
Updating joint map when a parent joint gets changed
added test for name map update when changing parent
fixing const-correctness
implemented a class for name management and applied it to BodyNodes, Joints, and Markers (in Skeleton) and Skeletons (in World)
Merge remote-tracking branch 'origin/master' into grey/name_manager
added BSD license to NameManager
fixing date on copyright
Fix typo in dart/collision/CMakeLists.txt
code quality changes
found more whitespace
Consistent Jacobian and its derivatives of BallJoint and FreeJoint
Merge pull request #284 from dartsim/joint_jacobians

Consistent Jacobian and its derivatives of BallJoint and FreeJoint
Merge remote-tracking branch 'origin/release-4.2'
Fix style
Merge remote-tracking branch 'origin/master' into grey/name_manager