renderer2: Loading screen
So idea is simple, when we are first starting up ETL and the game window pops up the window goes gray/black for a while until the intro or UI is loaded and it start drawing elements to the screen. We should draw the legacy icon to the center of the screen so that people know that something is actually happening.
This comes even more important with the renderer2 implementation which takes a while to compile (or load) the shaders and the windows actually stays gray for a long time. In ren2 we will actually need to compile an über simple shader that only does this one thing before anything else (right after opengl context is created and setup is complete).