Let there be light

And there was light!
For now there is no scene graph or property implementation, all lights are added in painter.cpp, check that out to see how you can add lights.
You have your shader with an identifier, i.e. ```NUM_LIGHTS``` for light count and with glow you can replace that string within the shader with the actual value, that will be  ```const int MAX_NUM_LIGHTS``` as Daniel mentioned. (before compiling the shader)