CoM constraints, enums, clean up

src/PreviewControl/SupportFSM.cpp

src/PreviewControl/SupportFSM.h

src/PreviewControl/rigid-body.hh

src/ZMPRefTrajectoryGeneration/ZMPVelocityReferencedQP.cpp

src/ZMPRefTrajectoryGeneration/generator-vel-ref.cpp

src/ZMPRefTrajectoryGeneration/generator-vel-ref.hh

src/ZMPRefTrajectoryGeneration/qp-problem.cpp

src/ZMPRefTrajectoryGeneration/qp-problem.hh

src/privatepgtypes.h