Add a recovery behaviour once the global plan has not been updated for N planning periods

[rayvburn]

In such a case, try to implement a back-up recovery - move back until 3/4 of the circle around the robot (with a given radius) consists of the collision-free points.

It may be named as isGlobalPlanOutdated in the RecoveryManager. Requires setting a timestamp of the last global plan update in the planner's setPlan method.

[rayvburn]

Another solution can be as follows: treat the last non-collision pose of the newest available global plan as a temporary goal. When the temporary goal is reached and the global plan was not updated, let's try to apply the stop&rotate recovery or back-up recovery.