Instead us a Toolbox concept which hangs off of QGCApplication

Also turn them back on

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

Simple starting point to view testing

This was leftover from a problem I was having with virtual slots

Allows for UI unit tests to be written:
- Ability to respond to expected message boxes
- Ability to fail test if unexpected message boxes occurs

Used for unit testing