[CMake] clean: keep minimal required instructions

CMakeLists.txt

cmake

examples/CMakeLists.txt

examples/inverse_pendulum/CMakeLists.txt

examples/inverse_pendulum/costIP.cpp

examples/inverse_pendulum/costIP.hh

examples/inverse_pendulum/mainIP.cpp

examples/inverse_pendulum/modelIP.cpp

examples/inverse_pendulum/modelIP.hh

examples/linear/CMakeLists.txt

examples/linear/costLinear.cpp

examples/linear/costLinear.hh

examples/linear/mainLinear.cpp

examples/linear/modelLinear.cpp

examples/linear/modelLinear.hh

examples/pyrene_actuator/CMakeLists.txt

examples/pyrene_actuator/mainPyrene.cpp

examples/pyrene_actuator/pyreneActuator.cpp

examples/pyrene_actuator/pyreneActuator.hh

examples/pyrene_actuator/pyreneCostFunction.cpp