validate.js: Unifying code to use one javascript framework

Tracker: [#30393](http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=30393)


I added small feature to suppress showing validation errors (ie. from within template), invalid input fields and labels receive class 'invalid' anyway

```JAVASCRIPT
// In case script validate.js is being loaded after template.js use 'onload' event
window.addEvent('domready', function(){

	// Configure document validator
	if ( document.formvalidator )
	{
		document.formvalidator.suppressMessages = true;
	}
});
```