Add `refractionIndex` field to `Ray`
Refraction test scene
Ideal transmission
Add current render example
Add specular transmission exponent property to materials
Add specular transmission term (light through glass)
Add some explicit dependencies
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 #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
Merge pull request #18 from merlinND/renderer

Specular lighting (glass)
Texture stubs
Plain uniform color texture
Objects have a Texture, not a simple Color