RC and manual control fixes

 - RC timeout / lost signal handling improved: if 'rc_lost' flag received or throttle failsafe detected (smart receiver already reached timeout) don't wait for timeout in commander but switch to failsafe state immediately, but for stupid receivers timeout increased to 0.5s
- `manual_control_setpoint` topic now contains values -1..1, not scaled by `RC_SCALE_ROLL/PITCH/YAW` (parameter removed)
- attitude/position controllers has own scaling factors where needed