tools/gen-sat-catalog.py: Create new XML catalog

The gen-sat-catalog utility has been adapted to create the new
well extensible XML catalog format.
tools/gen-sat-catalog: Add XSLT for transforming catalog to legacy format
introduce MarbleView
introduce MarbleGLView
introcude GlLayerInterface
clear depth buffer between layer rendering
TextureLayer
PlacemarkLayer
introduce triangulation algorithm for polygons

* taken from http://www.crystalspace3d.org/svnroot/crystal/CS/trunk/{include/csgeom/triangulate.h, libs/csgeom/triangulate.cpp}.
GeometryLayer
introduce GeoGraphicsScene::GlTile and use glDrawElements
adapt PlacemarkLayout
use shaders
GLRenderer