Revert changes made to materials (T_T)
CMakeLists.txt: add -Ofast
TODO:update thouroughly
Light: add support for radius and samples, handle soft shadows
    and manage materials
Material: redo parsing, patch typos
Scene: refactoring, remove soft_shadows function, move a lot of work in
    Lights
scenes/* : Update test files
Light; patch color model
Color: remove a dangerous constructor
Scene: add a forgotten variable
Utils: add randSphere function