Did some serious horsing around to be able to "hug" the ground properly
and still be able to take off.
Set the near clip plane to 1.0 meters when less than 10 meters above the
ground.
Did some serious horsing around getting the initial airplane position to be
correct based on rendered terrain elevation.
Added a little cheat/hack that will prevent the view position from ever
dropping below the terrain, even when the flight model doesn't quite
put you as high as you'd like.
Mesa/glu version.) But, by calculating the Model View matrix our selves
we can save this matrix without having to read it back in from the video
card. This hopefully allows us to save a few cpu cycles when rendering
out the fragments because we can just use glLoadMatrixd() with the
precalculated matrix for each tile rather than doing a push(), translate(),
pop() for every fragment.
Panel status defaults to off for now until it gets a bit more developed.
Extract OpenGL driver info on initialization.
Shuffled some additional view parameters into the fgVIEW class.
Changed tile-radius to tile-diameter because it is a much better
name.
Added a WORLD_TO_EYE transformation to views.cxx. This allows us
to transform world space to eye space for view frustum culling.
