Adding option to transform map based on header timestamp

[ayrton04]

Addresses #1065. Wasn't sure what name to give the property in the display window. I'm open to suggestions if anyone has any!

[NikolausDemmel]

LGTM.

The name is reasonable IMHO.

[wjwwood]

Cool, I'll try it out locally ASAP. @ayrton04 can you give an example scenario where I could test this out?

[ayrton04]

I'm afraid I don't have code I can share, but if you turn a delayed laser scan into an occupancy grid with a timestamp and frame_id of the laser scan itself, then it becomes easy to see the effect of the PR.

[ayrton04]

I've also found that just running a robot in sim and visualizing the local costmap works well. If it moves around a fair amount when the new parameter is set to false, it becomes much more stable after enabling it.

[wjwwood]

I tried using the examples in navigation_stage but I was unable to see the change you're talking about when enabling/disabling this option. Maybe you could make a short video/gif and upload it?

[ayrton04]

Sure, I'll do that.

[wjwwood]

I tried this again but I still couldn't see the difference. I must be doing something that doesn't exhibit the problem in the first place. Since the code lgtm and its hidden behind an option with a default behavior that hasn't changed, I'm going to go ahead and merge this. If someone else notices this doesn't resolve the problem we can fix it up then.

[ayrton04]

Apologies, @wjwwood. I am running Xenial/Kinetic, and was hoping to use one of the open-source robot sims to produce an example, but never found a Kinetic-friendly one, and didn't get around to building an Indigo install in Xenial.