dispatchEvent, avoid unnecessary apply and instanceof

Some whitespace removal as well because my editor just does that ;)

dispatchEvent changes are based on results from these (and my personal/professional experience of course):
http://jsperf.com/function-versus-function-call-versus-function-apply/11
http://jsperf.com/function-calls-direct-vs-apply-vs-call-vs-bind/5

Since there is just one argument, and you are not passing a context, `apply` and even `call` is not needed here. Also I thought just checking for the EventListener interface on the listener object was enough rather than doing `instanceof`.