Don't kill global events when shutting down skill
Don't kill global events when shutting down skill

During skill shutdown remove_all_handlers() was called on all registered
events. This would unregister all global events, such as settings
updating, stop for all skills.

Now the remove only will remove the instance connected to the skills
method.

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