Stable desktop version check

Show the link indicator in the tool bar if two or more links are connected and at least one of them is a high latency link.
Show in the link indicator if a link is inactive.

Converted Structure Scan to use CameraCalc such that it now works with
camera specs.

Also hand carried text to speech changes from Stable to master. Plus
unit tests for that.

This reverts commit 52160d80.

Switch test from 8.8.8.8:53 to "www.github.com:80"

Update the user model to a single controller instead of multiple

Instead of hardcoded "QGroundContorl" strings