AMD Radeon Performance Preview On Linux 3.8

Starting with the Nexuiz benchmark, the results were surprisingly quite mixed. For three of the graphics cards, the frame-rate is now much lower with the open-source Radeon Gallium3D driver when using the drm-next kernel. For the other graphics cards, the performance was basically unchanged.

OpenArena didn't see any performance changes out of the drm-next Radeon code.