Correct handling of terrain ready when loading back from file

Unit Test for Survey command sequence generation

Major rewrite of Survey generation for simplicity. Also includes support for CONDITION_GATE.

Unit test for mission transfer error string checking

Much better error reporting for Mission transfer errors

Plan: Add support for takeoff item required

Shape file examples for testing

Wizard mode should be off for loaded items

Clear wizard mode when loading from file

Fix alternate transect support

Fix ArduPilot fake home position handling

Mavlink terrain protocol support

Added compiler switch for developers to generate survey preset default json files for use as built-in survey presets in custom builds

Support for built-in preset delete prevention

Fix load order so isManualCamera returns correct value

Show errors from preset load failures

Fix Done Tracing <-> Done PolyFoo in wizard relationship

Fix waypoint linkage to first item

Avoid arrow positioning with take item

Fix typo

Track trace mode in polygon so we can use it to exit wizard mode

Fix current item updating after delete

Not setting _isIncomplete correctly was causing crash

Fix Plan insert Takeoff/Land for correct enable state and insert into correct place. 

Plan: Make PX4 VTOL takeoff work like fixed wing

Fix MAV_CMD_IMAGE_START_CAPTURE unit test usage for take photo

Fix MAV_CMD_IMAGE_START_CAPTURE usage

Update vehicle heading from possible item change

Always send MISSION_ITEM_INT to ArduPilot

Add support for incomplete segment visuals

When a child item is current show the parent as selected

64 bit fixes

Use consistent "Launch" naming

Support move item to previous item position

New constant name