Update test scene
Refactor scene info output
Base for adaptative oversampling
Avoid recasting one ray too many when oversampling
Bi-directional adaptative oversampling (much better)
No need to recast the center ray when oversampling
Add Parallelepipoid (+ refactor Cube)

A Cube is a particular case of parallelepipoid
Add parallelepipoids to test scene
Add lighting test scene
Refactor light participation computing
Basis for attenuation of lighting with distance
Attenuation function for punctual lights
Tweak test scene
Merge pull request #17 from merlinND/performance

Bi-directional adaptative oversampling
Merge branch 'master' into geometry

Conflicts:
	src/main.cpp
Merge pull request #20 from merlinND/geometry

Parallelepipoids (geometric object)
Merge branch 'master' into lighting

Conflicts:
	src/main.cpp
Merge pull request #19 from merlinND/lighting

Attenuation of light intensity with distance to source
Merge branch 'master' into renderer

Conflicts:
	Makefile
	src/main.cpp