Crash when minimizing window

[kyle-robinson]

Currently, when minimizing the editor window, the project seems to crash with the error, "Failed to create Texture for Render Target!" This seems to be an issue with recreating the render target in the Graphics class on maximize.

Proposed Solution
Pause all processing of the current level, including updating and rendering the scene, while the program is minimized. Since window messages are received into the WindowContainer class, this should still be feasible.