smooth triangles (aka Phong shading) extend Python binding to support vertex normals and smooth triangles make bunny.py and realtime_dragon smooth, and fix other demos for new triangle constructor add Vector::operator/=

demos/ModulePath
demos/*.png
demos/kdtree.obj
ccdemos/*.png
ccdemos/spheres_shadow
ccdemos/realtime
ccdemos/realtime_dragon
models/bunny
models/happy
models/dragon
bin/*