Use the correct camera reference in flight.

Camera.main is not reliable, because while initially in flight it
points to the flight camera (probably by chance), as soon as you
go to map mode it switches to some UI camera and stays on it, and
the PAPI lights stop making any sense whatsoever.
Merge pull request #10 from angavrilov/develop

Use the correct camera reference in flight.
Merge pull request #11 from asarium/develop

Prepare release 0.3.2