CartesianNaturalPositionController: added position only mode

...tControllers/NJointCartesianNaturalPositionController.cpp

...intControllers/NJointCartesianNaturalPositionController.h

...ionController/CartesianNaturalPositionControllerWidget.ui

...er/CartesianNaturalPositionControllerWidgetController.cpp

...ller/CartesianNaturalPositionControllerWidgetController.h

...ts/RobotUnit/NJointCartesianNaturalPositionController.ice

...API/libraries/core/CartesianNaturalPositionController.cpp

...otAPI/libraries/core/CartesianNaturalPositionController.h

...PI/libraries/core/CartesianVelocityControllerWithRamp.cpp

...tAPI/libraries/core/CartesianVelocityControllerWithRamp.h

...braries/natik/CartesianNaturalPositionControllerProxy.cpp

...libraries/natik/CartesianNaturalPositionControllerProxy.h