Separated trajectory pt into base class and cart/joint derived classes
Added framework of required functionality to TrajectoryPt classes
Initialize frames for Joint/CartTrajectoryPt
Combined into single library. Moved fixed poses out of TrajectoryPt base class.
Cleanup and consistency of terms and definitions.
Merge pull request #6 from dpsolomon/issue#3_trajpt_base_class

Issue#3 trajpt base class