Add collision avoidance settings to Safety Panel

Get rid of QGCView, QGCViewPanel and FactPanel. All messages and dialogs are now handled in the root window.

Grouped logging options within General Settings

Move position of HITL to bottom. Handle no SYS_HITL param.

Changed (selected) mission item color to primaryButton instead of buttonHighlight
Adjusted some colors for better contrast
Removed a few JavaScript exceptions caused by the order of object destruction

Also pull fixedWing directly from Vehicle

Android done.

UI Tweaks for all mobile platforms.

* PX4: Deal properly with optional components

* RC map UI: Offer better defaults and user guidance

Got the new BAT_LOW_THR parameter.