Added some basic color management for airspaces

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.

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.

More commonly known terminlogy