Harald JOHSEN:

Harald JOHSEN:

Changes
=======

- shadowvolume.cxx, renderer.cxx :
  - reduced the polygon offset a bit to eliminate some artifact ;
  - changed again the cleanup code for objects inside a tile because it could crash on rare occasion ;
  - the culling of shadow casters has been rewritten to traverse the scene graph, it should be
    a bit faster when there is a lot of objects ;
  - the range selector was not correctly handled, sometimes the wrong LOD was casting shadows.
  - added the option to display aircraft's transparent objects after the shadows, this will
    reduce the problem of shadows being hidden by the transparent object (propeller disk,
    rotor, etc). A side effect is that aircraft's transparent objects won't receive shadows
    anymore. This is usually a good thing except when the aircraft use a 'transparent'
    texture where it should not. A transparent texture in the plib context is a texture
    with an alpha channel or a material with alpha <= 0.99.

- model.cxx, animation.cxx, shadowvolume.cxx :
  - added an optional <condition> under the <noshadow> animation

- tower.cxx
  - correct a rare bug where all occurences of the aircraft are not deleted from the
  departure list causing a crash in FGTower::CheckDepartureList function.