Add flight plan deletion

Moved flight planning away from "Flight Management" to its own class. Planning does not need a connected vehicle.

AirspaceManager is now exposed by QGroundControlQmlGlobal instead of Vehicle (available all the time)

Add highLatency property to LinkConfiguration

Fix bugs in updating priority link

Camera Control

Support remainder of HIGH_LATENCY2 fields

* Also handles correct prioritization of high latency links

Corridor Scan: applyNewAltitude support

UDP Change

Fix package generation

package directory was showing up in dmg file

Switch to using ROI_WPNEXT_OFFSET

Plus various bug fixes from flight testing

Also remove custom gimbal support

Corridor Scan: Support for images in turnaround

Fix multiple selected state for offline maps buttons.

More work on better unit tests

And fixes they found