- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

This wasn’t quite coded correctly. Mavlink needs heartbeat first, then
the shell command will be issued.

Preparation for auto-connect having no connect/disconnect buttons.

Tweak toolbar height for mobile.

It was using wrong size variable (and consequently too big)