UI Tweaks for all mobile platforms.

* Remove leftover debugging message
* Fix segfault on Linux at close for #3164

- Also fix vehicle selector dropdown in toolbar

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Now I'v discovered a Slot that returns a bool, this is not very
good because Qt expects a slot to have the same return type
as the signal, void, always.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

that was connected to showNormal, which always led to a smaller
minimized window irrespective of whether the applicaton was
full screen or not. Now it checks and always returns to maximized.

- 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

- 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

- 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

Instead us a Toolbox concept which hangs off of QGCApplication

When you selected via the Menu to go to Fly Mode, the QML
toolbar didn't followed the option, and if you selected
via the menu to go to all the three possible views (setup,
fly and plan) the menu would be all-selected.

This tries to keep consistency of things.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>