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/=
================== Pyrit Ray Tracer==================License-------Currently unlicensed, you may not redistribute or use this work for any purposes.Will be MIT licensed when ready.Pthreads--------Threads can be used to render rows of picture paralelly. Arbitrary numberof threads can be used, even numbers like 17 are acceptable.To completely disable this feature just remove "-DPTHREADS -pthreads"from flags in makefile.For Windows + Mingw32, get pthreads library here:http://sources.redhat.com/pthreads-win32/