Finds all child nodes that matches truth test for passed
<code>fn</code> function
@param {Function} fn
@returns {Array}
function(fn) {
			if (!_.isFunction(fn)) {
				var elemName = fn.toLowerCase();
				fn = function(item) {return item.name().toLowerCase() == elemName;};
			}
				
			var result = [];
			_.each(this.children, function(child) {
				if (fn(child))
					result.push(child);
				
				result = result.concat(child.findAll(fn));
			});
			
			return _.compact(result);
		}