Fly View: Move business logic inside controls

More work on crash fixes

Fix unit test crash

Add support for Json file string translations

Major update to simplify and document the custom build example

New LandingComplexItem base class for landing patterns

Fix OSX compile

Major rework to support terrain profile display and terrain collision reporting

Propagate opacity and interactive properties to mission items
Set opacity to 0.5 for items that are not part of the current
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