SimpleTextArea's onInput stops an event that may not be present

[Ben Lowery]

_onInput: function(e){
		// Override TextBox._onInput() to enforce maxLength restriction
		if(this.maxLength){
			var maxLength = parseInt(this.maxLength);
			var value = this.textbox.value.replace(/\r/g,'');
			var overflow = value.length - maxLength;
			if(overflow > 0){
				dojo.stopEvent(e);

The event may or may not be passed, as subclasses, like Textarea, call _onInput to do other input validation, not in the context of an event that needs stopping. We should check to make sure e is provided before stopping it.

[Ben Lowery]

(In [17852]) fixes #9389. check for existance of event before stopping it.

[bill]

(In [17854]) Use brackets for if() statement as per coding standards. Refs #9389.