Added disengageGears(), engageGears(), and pause() static methods. The first two are hacks that provide the illusion of interrupts for robot_script scripts. All robot_script user-level functions now have an intro idiom that checks a 'gears-engeged' flag. If gears are disengaged, the functions will return immediately. An event callback can disengage gears, and thereby short-circuit all of the main thread function's remaining actions. Drawback is that users must remember to call engageGears() again. The pause() method replaces robot_script's sleep call, which previously had end users use rospy.time.sleep(). The pause() method honors the gear method of interrupts. Updated the wiki accordingly. Still remaining: the flakey base motion.