Sorting source and headers while at it.

Initial rendering of Waypoints

QGCUASParamManager and friends are replaced by FactSystem

I forgot an extra argument for debugging (and didn't have WarningsAsErrorsOn properly set)
No idea how that emit qDebug ended up in there.

Removed left over debug message.

- All resources are either under src or under resources dirs
- Removed files top level directory
- Move flightgear files to top level dir

Also many LinkManager API changes to further isolate all link
management inside LinkManager.

Moved update canvas signal to perspective load instead of hooking it to the paint event.
Added an "S" as the unit for the number of cells fact (as in 4S).

Created new ScreenTools exported control for QML code to obtain screen DPI factor to be used for computing font point sizes. This code used to be in the tool bar code and now is available to all QML widgets.
Moved global mouse position tool into ScreenTools as I felt it would be a place to collect these sort of functionality.
Replaced Tree used in the Safety Component from a PNG file to a SVG file as the PNG was not scaling up properly.