Revert "Encapsulation, name changing"

...otTrajectoryGeneration/OnLineFootTrajectoryGeneration.cpp

...FootTrajectoryGeneration/OnLineFootTrajectoryGeneration.h

src/Mathematics/FootConstraintsAsLinearSystemForVelRef.cpp

src/Mathematics/FootConstraintsAsLinearSystemForVelRef.h

src/ZMPRefTrajectoryGeneration/ZMPVelocityReferencedQP.cpp

src/ZMPRefTrajectoryGeneration/ZMPVelocityReferencedQP.h

tests/TestHerdt2010.cpp