Implementing throttle axis accumulator with deadband support

Use FTDI driver provided by ftdichip.com

- Fixes lost connections with FTDI radios
- Modified code to only test vendor id, all product ids are let through
- Modified code to pass log output through to C++ side
QGCLoggingCategory system

Multicolored polygon

Fix brand image visibility calculation

Temp removal of Onboard Files

- fixes #4148

Added a second polygon. This polygon is updated from the first polygon at each mouse click and is what will ultimately be saved upon completion of drawing.

Update VTOL command text

Update message

Too buggy to leave in for now

Fix line back to home for VTOL takeoff

Adjust incoming message on channel 0

SDL2: Add missing Info.plist file for SDL2 framework.

Use single mavlink_status_t array

Update MAVLink parameter definitions for ArduSub

Add ArduSub firmware branding

ArduSub Safety Tab and Lights Tab