MDL-10249 Created addonload JavaScript function that can be used to add onload handlers, instead of using <body onload> which breaks things.

lib/javascript-static.js

@@ -420,3 +420,17 @@ function insertAtCursor(myField, myValue) {
         myField.value += myValue;
     }
 }
+
+
+/*
+		Call instead of setting window.onload directly or setting body onload=.
+		Adds your function to a chain of functions rather than overwriting anything
+		that exists.
+*/ 
+function addonload(fn) {
+    var oldhandler=window.onload;
+    window.onload=function() {
+        if(oldhandler) oldhandler();
+		    fn();
+    }
+}