Commit about Arducopter, with license compatibliity?

[quietlychris]

First, I just want to say I think this project is really exciting, and opening issue is meant constructively, not aggressively, and I hope it comes off that way.

I saw the commit note in 3e43374 and was a bit concerned about license compatibility, especially since this project appears to still be fairly early on in development. My understanding is that ArduCopter, as a part of the larger Ardupilot codebase, is licensed under GPLv3 (per this link). That means that any import, even as a re-write in a different language, could potentially be considered a license violation since embedded-flight is currently under the permissive MIT license instead.

I believe that APIs themselves can be re-produced without violation, but using the code itself as a template could be a bit sticky vs. implementation from a "clean room" approach. Again, I'm not sure what process you used, but especially since this is now in the current commit logs, I'd like to encourage you to clarify this in some way in order to make sure that ambiguity around licensing wouldn't pop up in the future. Thanks for your consideration of this!