Removed unnecesary files
Cleaning OCP and NLP classes
Fixing objective and constraint classes

- Objective classes prepared for the new matrix/vector API.
Fixed a stupid big in ExportFunction

related to stream-to-stream printing...
Fixing ExportNLPSolver for the new API
Cleaning and fixing ExportIndex class
Fixed internal of export variable
Fixed a small bug, 0 -> "", in OCP export
Fixed some CGT examples + ...

closed loop examples are disabled for the moment.
CGT is enabled in the main CMake sctipt + ...

- CGT is not any mode in the optimal control header but in the
  main acado_toolkit.hpp.