Critical fix for Airbrush, to prevent it from spiraling to death when airbrushing time-consuming brushes : Event queue would fill with 'tick' events, mouse button release wouldn't be caught, more airbrushing , more cpu cost, deadlock

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1569 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/input.c

@@ -779,7 +779,7 @@ int Get_input(void)
                 break;
             
             case SDL_USEREVENT:
-                user_feedback_required = 1;
+                //user_feedback_required = 1;
                 break;
             default:
                 //DEBUG("Unhandled SDL event number : ",event.type);