Move scenegraph source to subdirectory scenegraph.
Take PolygonalGeometry out of scenegraph tree. Further devide responsibilities between PolygonalDrawable andPolygonalGeometry.
...
issue #3: Add scene graph iterator and traverser.
Add DrawTraverser.
issue #3: Refactoring.
issue #3: Change DrawTraverser to DrawVisitor.
issue #3: update CMakeLists.
issue #3: Move gl buffer handling from PolygonalDrawable to PolygonalGeometry. Some Refactoring.
issue #3: Add interface for scene graph visitors.
issue #3: ...
issue #3: Attempt to fix a compile error with MSVC.
issue #3: Add break condition to SceneTraverser.
issue #3: ...
issue #3: Delete Iterarator hierarchy. Refacrtor.
issue #3: Use central DataBlockRegistry object for grometry data.
ref #77 Add empty shader for pathtracing testing.
ref #77 attached vertices, normals and (empty) geometry data to shader as buffer texture.

Data format seems to be wrong. Maybe we have to copy the data to a vec4 array? http://www.opengl.org/wiki/Buffer_Texture#Image_formats
ref #77 Texture Buffers working.

Shader can access vertex, normal data and (still empty) geometry array.
Test shader searches the nearest vertex for each fragment and uses its normal as color.
Merge remote-tracking branch 'origin/master' into PathTracingGPU_77

Conflicts:
	apps/cgsee/painter.cpp