Instead us a Toolbox concept which hangs off of QGCApplication

- Fixed bugs found to unit test

- fix bugs found by test
- Implemented Mock mission item protocol in

The goal of this first installment is to organize the code a bit so it's more readable,
clean up a bit of left over cruft, and manage link configurations (and links in general).

Handy for testing without a real board

Working on better simulation implementation, fixed a bug where the port handle was not fully released