Fixing reference counting of event handlers in the simulator runtime (#547)
Fixing reference counting of event handlers in the simulator runtime (#547)


Microsoft/pxt,playi/pxt,Microsoft/pxt,Microsoft/pxt,switch-education/pxt,switchinnovations/pxt,playi/pxt,switch-education/pxt,Microsoft/pxt,switch-education/pxt,Microsoft/pxt,switchinnovations/pxt,playi/pxt,switch-education/pxt,switchinnovations/pxt,switchinnovations/pxt,playi/pxt,switch-education/pxt