shader/scene refactoring, including interface changes in regards to switching...

shader/scene refactoring, including interface changes in regards to switching shading modes (see Scene::SetShadingMode)
GUI 3D Window shortcuts changed (CTRL + 1=fallback, 2=basic, 3=default, 4=hemilight, 5=toon1, 6=toon2, P=shadow toggle)
fraglight shadow/non-shadow and basic shadow/non-shadow shader consolidated into one each
moved some state management into Shader class to improve interface separation
some more work in disentangling gfx_obj, entity, vertex_array states and rendering modes
implemented quad based line-bluring for LineTraceRenderer (a bit hackishly)
moved said line-bluring control to entity level, and actual rendering outside to entity_detail
(re/un/)fixed cartoon rendering twisting artefacts



git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/branches/new_gfx@2146 5a81b35b-ba03-0410-adc8-b2c5c5119f08