Only allow one repeating even of each type
Only allow one repeating even of each type

Previously if duplicates of a skill should be launched or a skill isn't properly
shutdown when reloaded multiple handlers could be registred. This commit disables multiples of repeating events.

forslund/mycroft-core,forslund/mycroft-core,MycroftAI/mycroft-core,MycroftAI/mycroft-core,Dark5ide/mycroft-core,linuxipho/mycroft-core,linuxipho/mycroft-core,Dark5ide/mycroft-core