Add realtime action server goal handle.

[adolfo-rt]

• Factored out from PR2's implementation of the JointTrajectoryActionController.

This is a prerequisite for the Joint Trajectory Controller

[davetcoleman]

I don't exactly understand what makes this action server handle real time, but I suppose you wrap this within another realtime tool?

[adolfo-rt]

The runNonRealtime() method has to be executed from a non-realtime thread, and is meant to be called periodically by a timer event.

I admit to the class not being documented and not explaining its usage, another todo...

Originally this was part of the PR2's controller, but my thought was that it could be useful in other controllers. If the usecase seems too narrow and specific, I'd consider adding this file to the JointTrajectoryController package instead of here.

[davetcoleman]

my thought was that it could be useful in other controllers.

Yes, I think this was a good thought. It make sense to me now, I think it should be merged.

[adolfo-rt]

Ping. I'm not a collaborator in this repo, so I can't merge this PR.

[adolfo-rt]

Thanks @ahendrix

[ahendrix]

Released as 1.8.2: ros/rosdistro#1901