So this special casing is no longer needed

If it doesn’t exist it will be prefilled with all registered categories
set to false

Changed settings version as the link configurations must be redone (with the new port names)

Otherwise some messages say 'System MAV 0-20' and some say 'System 20'.

Should fix things.

FactTextField, when setting the value from its "text" field, was converting the value to string. This was causing (QML JavaScript) code that uses the value for computation to stop working once the user changed the value.

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).

Also changed to qWarning

Added "Advanced Settings" check box.

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.

Tool bar buttons now use QGCButton as base to inherit hover mode fix.
Made QGCButton.showHightLight into a public property so I could use it as a trigger for repainting the chevron button.

Also realized I don’t need __lastMouseXY

Reduced size of the main tool bar buttons accordingly.
Connect/Disconnect buttons (and link configuration combobox) now use the default height.