- use strings for fg_root and airport_id and added methods to return
them as strings,
- inlined all access methods,
- made the parsing functions private methods,
- deleted some unused functions.
- propogated some of these changes out a bit further.
but seems to be triggering a bug.
light.cxx: Added code to adjust fog color based on sunrise/sunset effects
and view orientation. This is an attempt to match the fog color to the
sky color in the center of the screen. You see discrepancies at the
edges, but what else can be done?
sunpos.cxx: Caculate local direction to sun here. (what compass direction
do we need to face to point directly at sun)
