ADSB server support provided through new ADSBVehicleManager implemenation

Handled "airspace visible" state (not done)
Adjusted restriction map items color and opacity
Added/Updated icons for airspace traffic
Adjust colors for text over maps

Plus low battery announce changes

Plumb through initial object mode on Vehicle

This is the Pixhawk research board, not the PX4 production board.

Erros casused by all of the mergedd branches are now fixed for qgroundcontrol.pro. Working on fixing the errors that now appeare in qgcunittest.pro.

qgcunittest.pro now compiles and runs as long as run in terminal in projcts->Run Settings is unchecked.

Replaced the autopilot-specific inclusion of MAVLink to be more generic. Now if you have no actual QGC modifications to make and just want your messages to be available for viewing/logging you can just create the user_config.pri file and override MAVLINK_CONF.