added the dom events API to the kotlin standard library and get it compiling as JS too (not unit tested yet mind you ;)

js/js.libraries/src/core/domEvents.kt

@@ -38,12 +38,8 @@ native public trait Event {
     }
 }
 
-native public trait EventListener {
-    public fun handleEvent(arg1: Event): Unit = js.noImpl
-}
-
 native public trait EventTarget {
-    public fun dispatchEvent(arg1: Event): Boolean = js.noImpl
+    public fun dispatchEvent(arg1: Event?): Boolean = js.noImpl
     public fun addEventListener(arg1: String?, arg2: EventListener, arg3: Boolean): Unit = js.noImpl
     public fun removeEventListener(arg1: String?, arg2: EventListener, arg3: Boolean): Unit = js.noImpl
 }

js/js.libraries/src/core/domEventsCode.kt

@@ -0,0 +1,15 @@
+package org.w3c.dom.events
+
+import org.w3c.dom.*
+import org.w3c.dom.views.*
+
+/*
+  TODO we should maybe update GeneratedJavaScriptStubs.kt to auto-create this file
+  too so that we can have the implementation code generated for JS
+
+  See: https://github.com/JetBrains/kotlin/tree/master/libraries/stdlib
+*/
+
+public trait EventListener {
+    public fun handleEvent(arg1: Event?): Unit = js.noImpl
+}