This adds support for the full-sized FMUv4PRO design and the FMUv5 STM32F7 based generation.

* Fix minor spelling error

* Added support for the AUAV x2.1 Flight Controller
    also removed a duplicate entry for MindPX
    from src/comm/USBBoardInfo.json

Adds entries required to correctly identify, download and flash PX4
firmware to the AUAV X2.1 Flight Controller

* Update USBBoardInfo.json

Removed un-needed fallback entries. This has been tested!

* Add support for another board

* Added a 2nd custom board

- 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

Also enable identification of clone 3dr radios

Usability plus, new features:
- 3DR Radio support
- APM Stack support

Also updated parser for new xml format

- Much simpler UI
- MVC style qml programming model

QSerialPort buffering too slow on Windows.