Allow plugin to add flight modes to joystick button actions

Work around message disassembly issue on ARM 32-bit.
Fix memory leaks.

Allow plugin to add flight modes to joystick button actions

QGC is not using Jenkins actively for QA or binary building and is using QMake as build system (not CMake as Jenkins is). Maintaining two ways of doing things dilutes the limited time available for QA and CI maintenance and Travis / Github actions plus AppVeyor work perfectly fine.

Move analyze page list model to the core plugin.

Tweak chart colors

UI tweaks

Limit chart to 6 series (arbitrary)
UI tweaks

WIP - MAVLink chart as a control. Add any number of charts with any number of series. All individually controlled.

Add custom chart header

Stable sync

Stable sync

Update Ardusub Metadata and Tuning page for Sub 4.0

Don't show GCS heading unless it comes from plugin

Heading value should be real so NaN comes through

Only trust gcs heading from plugin

Fix MAV_CMD_IMAGE_START_CAPTURE usage