new EffectsCatcher released

A new ArtOfIllusion plugin, "EffectsCatcher" has been released in the repository.

This is the reimplementation of the original "transparent shadow" logic in the AdvancedRenderer.

EffectsCatcher allows any objects in the 3D scene to be configured as effects catchers.
Each effects catcher object supports any combination of:
* shadow-catcher
* illumination-catcher
* reflections catcher

In addition, effects can be rendered in either colour or greyscale.

See this thread in the ArtOfIllusion forums for more detail:
http://sourceforge.net/forum/forum.php?thread_id=3192262&forum_id=47782