Use correct terminology for Altitude values

FW Landing Pattern: Support for stop photo/video. Plus item unit test.

Fix Plan save message on exit

Replacing colors with the ones provided by Airmap.
Adding border color and width.
Adding airspace ID so it can later be linked to the advisory list.

Added some basic color management for airspaces

Hide flight speed and camera section for ArduPilot. This is because it doesn't allow mission items to be before the TAKEOFF command.

Change Command only supported for Simple Items

Fix editor sizing

Handle flight start/end time
Handle start/stop traffic monitor
Only start telemetry if enabled
Added a "Now" button for the flight start time
Collect advisories only when the rules change

This is in addition to the existing text edit control.

This is in addition to the existing text edit control.

Updates in general was only done if a POI changed. This caused changes related to something other than a change in POI to be ignore. The code now "resets" the POI when such changes occur (change of ruleset for example).
Ruleset selection is was not persistent. When reloading the list of rulesets for a given region, any previously selected ruleset would be reset to defaults.
Also fixed several new clang warnings.

This way you can click anywhere

* Load Plan
* Save to KML
* Load Plan (it tries to load KML instead)

Create new, specific button for clearing mission from vehicle
Adjust sizing of DropPanel

This was too confusion to expose since QGC currently does not support ArduPilot terrain tile send.