DOF, debugging
DOF Effect seems to work now.
Interactiv gui
Merge branch 'master' of https://github.com/HichamBenjelloun/Raytracer

Conflicts:
	Makefile
	src/engine/src/RaytracingEngine.cpp
	src/engine/tests/test_engine_depthBlur.cpp

Merge with Hicham DOF