Fix for a memory leak in dispatchEvent()
Fix for a memory leak in dispatchEvent()

The array in question grows with duplicate entries everytime
dispatchEvent() is called when mixing onfoo="" with
addEventListener("foo", ...)

selam/jsdom,cpojer/jsdom,cpojer/jsdom,susaing/jsdom,Ye-Yong-Chi/jsdom,mzgol/jsdom,selam/jsdom,AVGP/jsdom,Sebmaster/jsdom,mzgol/jsdom,mbostock/jsdom,fiftin/jsdom,nicolashenry/jsdom,tmpvar/jsdom,Sebmaster/jsdom,mzgol/jsdom,vestineo/jsdom,susaing/jsdom,mbostock/jsdom,danieljoppi/jsdom,jeffcarp/jsdom,darobin/jsdom,zaucy/jsdom,vestineo/jsdom,sirbrillig/jsdom,evdevgit/jsdom,evdevgit/jsdom,AshCoolman/jsdom,szarouski/jsdom,evanlucas/jsdom,robertknight/jsdom,janusnic/jsdom,nicolashenry/jsdom,sebmck/jsdom,Zirro/jsdom,crealogix/jsdom,snuggs/jsdom,medikoo/jsdom,zaucy/jsdom,darobin/jsdom,danieljoppi/jsdom,sirbrillig/jsdom,medikoo/jsdom,mbostock/jsdom,Joris-van-der-Wel/jsdom,zaucy/jsdom,beni55/jsdom,lcstore/jsdom,kesla/jsdom,kittens/jsdom,medikoo/jsdom,jeffcarp/jsdom,Joris-van-der-Wel/jsdom,sebmck/jsdom,fiftin/jsdom,szarouski/jsdom,kevinold/jsdom,beni55/jsdom,evanlucas/jsdom,Ye-Yong-Chi/jsdom,janusnic/jsdom,Ye-Yong-Chi/jsdom,evdevgit/jsdom,Joris-van-der-Wel/jsdom,vestineo/jsdom,janusnic/jsdom,kesla/jsdom,selam/jsdom,sebmck/jsdom,aduyng/jsdom,kevinold/jsdom,kevinold/jsdom,szarouski/jsdom,tmpvar/jsdom,aduyng/jsdom,kittens/jsdom,beni55/jsdom,evanlucas/jsdom,robertknight/jsdom,susaing/jsdom,lcstore/jsdom,nicolashenry/jsdom,lcstore/jsdom,Zirro/jsdom,sirbrillig/jsdom,fiftin/jsdom,AshCoolman/jsdom,crealogix/jsdom,aduyng/jsdom,danieljoppi/jsdom,snuggs/jsdom,Sebmaster/jsdom,kesla/jsdom,AVGP/jsdom,AshCoolman/jsdom,kittens/jsdom,jeffcarp/jsdom,cpojer/jsdom,darobin/jsdom,robertknight/jsdom