Tree code size reduction

[Les]

This Tree code fragment can be reduced b/c dojo.removeClass now accepts arrays.

dojo.forEach(styles,
	function(s){
		dojo.removeClass(this.expandoNode, s);
	}, this
);

New code:

dojo.removeClass(this.expandoNode, styles);

[bill]

OK, thanks, will fix.

[bill]

(In [20301]) Tree code size reduction, thanks Les. Fixes #9989 !strict.

[bill]

seems like these aren't really enhancements from the users' point of view, labeling as tasks instead