Adds airsim_ros package supporting Redtail simulations in AirSim

[TritonSailor]

This PR adds a new airsim_ros package with ROS nodes providing initial support for Redtail simulations in AirSim. The package also contains a demo launch file for the Jetson Xavier running a Redtail navigated APMrover SITL simulation in AirSIm

This commit will be followed shortly with a wiki doc explaining installation and use, a demo video, and a forest trails UE4 environment packaged for Windows and Linux.

[Alexey-Kamenev]

This is awesome, thank you! Let me review/test it more thoroughly next week...

[TritonSailor]

Here's a link to the Win64 binary for Redtail UE4 environment.

https://www.dropbox.com/s/7p55uwhaigohu4r/Redtail.zip?dl=0

[TritonSailor]

Link to the Linux binary for Redtail UE4 environment. Windows version is significantly faster, also has Nvidia VXGI integrated. Linux version is available for testing, but needs much more optimization. Not recommended yet for actual use.

https://www.dropbox.com/s/iuzh03fm76vinzq/Redtail.tgz?dl=0

[Alexey-Kamenev]

Sorry, it's taking longer than I expected - I was at IROS last week, so need to catch up at work first.

[TritonSailor]

Sounds good, I've got a waveworks environment with a bouyant boat that can be controlled by redtail that I'll be adding soon. It has a yacht that can steer around other boats or partly submerged shipping containers to start with. I can add more complexity to the sim after we get redtail to handle the simple cases well.

I'm also planning to release updated versions of the forest trails environment with optimizations and improvements.

[TritonSailor]

Not sure if you already found this. Here's the documentation I've got so far:

https://github.com/TritonSailor/redtail/wiki/Getting-Started-with-Autonomous-Navigation-Training-and-Testing-using-airsim_ros-package