Initial commit.

- add vec3, matrix4
- add makefile
- add .gitignore
- add main()
Add test files, and fix filename mzrender.cc -> nzrender.cc .
Fix dependencies in makefile.
Fix Makefile to output object files into 'out' subdirectory.
Fix Makefile around 'out' directory because directory's timestamp is updated when inner files are updated and cannot be used in dependency.
Fix Makfile a bit.
Add triangle class.
Remove unsed prec.cc
Add vec3 output operator << and fix operator == (add const)
Add incomplete obj file parser and its test files.
Add Intersection class and precompiled header for nzrender_test.
Add Image class and boost::gil, libjpeg, libpng link.
Add KdTree and Box classes.
Fix dependency in makefile.
Add render main path, color, camera, light...
Add scene file parser and DirectionalLight.
Add normal setting.
Add simple shading.
Add simple shadow processing.
Merge remote-tracking branch 'github/master'