Add current render example
Recursion stopping criterion
Choose the test scene's background color at random
Algorithm prep for color computation
Merge branch 'master' into renderer

Conflicts:
	src/renderer/Renderer.cpp
Basic punctual lighting
Remove ambiguous Image constructor
Fix cube intersection not returning the correct normal vector
Basic diffuse lighting
Add current render example image
Basic oversampling
Merge branch 'master' into geometry
Merge branch 'renderer' into geometry
Add sphere to test scene
Sphere intersection computation
Allow to skip the computation of the point of intersection
Merge pull request #7 from merlinND/geometry

Sphere