Added libaries to project structure.
Added 3 light sources:
  * direct
  * 2 splotlight
Addded new spotlight model. Added objects to scene.
Refactoring:

  * remove useless shaders files
  * renamed used shaders files
Added bench *.obj, *.mtl files and added benchs to the scene.
Change material colors in Model.h and scene.f.shader from vec3 to vec4.
Added default 4th parameter to ModelAsset::init for passing material diffuse color.
Added room object. Added 2 directional lights.
Added 2 direction lights and 4 spotlights.
Now window can be resized by user.
Refacroting.
Refactoring:
  * rename namespace tdogl to gk3d
Added README.md