[rotorcraft] check_in_flight without RC

Closes #464
Changes to make ARDrone2 SDK fly without joystick
Still needs to be properly solved as per issue #201
[conf] update example sessions for ARDrone2

Removed Logitech Joystick because users are not going to have it and it will cause error messages when they launch it.
Adding notes in Wiki on how to add joystick yourself.
We now only need one session for ardrone2
[release] v5.0 stable version