Better handling of resume mission upload failures

Internet availability test fixes

Mission upload: Extra paranoia around write index list

Mission/Survey related fixes

* If new Survey is set to altitude fixed value then use mission default
altitude
* If the user applies a new altitude to the entire mission change
surveys to fixed altitude and apply altitude

This way if the user switches away from manual the altitude is preserved

Correct hiding of heading on TAKEOFF command

Plan: Update home position when loading plan after vehicle already connected

GeoFenceManager: Add missing signals

Update for ArduCopter 3.5 release

Allow custom overrides of windows installer icons

Resume mission shows up at wrong times

Handle bogus lat/lon from ArduPilot

Stable fixes

iOS fixes

Hide "Save Path" as it breaks the UI in General Settings.

New polygon center calc

Hide wind rose until bugs are fixed