Growl, Contact widget, Lazy execute JS, Error handling lazy loading JS

* Tuned growl closing; sometimes growl boxes weren't closed correctly
because the close was invoked before the dom was started. Fixed.
* Implemented lazy execute JS function; invokes a js function in lazy
loaded JS file; currently used by contact widget; should be used by
other functions too. Will help reduce size of HTML and # of requested
files and improved performance.
* If script/css is lazy loaded, system will now output errors (on
limited browsers) if the resource cannot be loaded (404). This helps
identify risks prevent problems.