Rover: Creating Rover v3.1.0beta6

Copter: version to 3.4.2

Copter: version to 3.4.2

Copter: version to 3.4.2

Copter: version to 3.4.2

Copter: version to 3.4

Plane: reduce change of false rangefinder readings triggering a flare

This doesn't count repeated readings towards the rangefinder count,
and resets the counter if the change is more than 20% of full
range. This greatly reduces the impact of poor sonar sensors for
landing

Plane: change version to 3.7.1

Plane: change version to 3.7.1

Plane: final release notes for 3.7.0