Debug drawings

Debug drawings for point, line, and cube. Basically:
void DebugDraw::DrawPoint(glm::vec3 position);
void DebugDraw::DrawCube(glm::vec3 position, float size);
void DebugDraw::DrawLine(glm::vec3 from, glm::vec3 to);
void DebugDraw::DrawLine(glm::vec3 from, glm::vec3 direction, float length);

Turned out to be much simpler when i decided to just use fixed function pipeline. I mean, its just debug. So i decided i won't worry too much.