Converted Structure Scan to use CameraCalc such that it now works with
camera specs.

Also fixed bug with ArduPilot guided waypoint write which would trash
existing mission.

Fix crash when adding second structure scan

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

save to kml use double number with 10 valid digits。

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

* Resume index adjust to previous coordinate command
* Takeoff always added to resume mission
* Remove camera id checks which are no longer part of spec
* Simplified de-dup logic

* 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