WM Draw Methods now has a new option Automatic (default). This will

set the draw method to triple buffer or overlap depending on the
configuration. Ideally I could get all cases working well with triple
buffer but it's hard in practice. At the moment there are two cases
that use overlap instead:

* opensource ATI drives on linux
* windows software renderer

Also added a utility function to check GPU device/os/driver.

release/scripts/ui/space_userpref.py

@@ -467,7 +467,7 @@ class USERPREF_PT_system(bpy.types.Panel):
         #Anti-aliasing is disabled as it breaks broder/lasso select
         #col.prop(system, "use_antialiasing")
         col.label(text="Window Draw Method:")
-        col.row().prop(system, "window_draw_method", expand=True)
+        col.prop(system, "window_draw_method", text="")
         col.label(text="Textures:")
         col.prop(system, "gl_texture_limit", text="Limit Size")
         col.prop(system, "texture_time_out", text="Time Out")