Made progress on lighting

Updated submodule DMath to latest version
Updated Mesh shader to use Phong lighting (only diffuse and specularity atm).
Changed default window size to be slightly larger yet fit on 1080p.
Added GetModel functions to Camera component.
Updated test scene in Engine.cpp
Fixed Camera world-space position calculation bug.
Renamed Renderer::CameraInfo::ProjectMode to ProjectionMode.

Signed-off-by: Nils Petter Skålerud <np_skalerud@hotmail.com>