If the OpenGL renderer is selected for a non-OpenGL window, recreate the window with OpenGL enabled.

Added OpenGL renderer error checking.
Use fast-path texture formats in the OpenGL renderer.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401969

test/common.c

@@ -55,9 +55,6 @@ CommonArg(CommonState * state, int index)
         if (!argv[index]) {
             return -1;
         }
-        if (SDL_strcasecmp(argv[index], "opengl") == 0) {
-            state->window_flags |= SDL_WINDOW_OPENGL;
-        }
         state->renderdriver = argv[index];
         return 2;
     }