Effects: Allow all "effect" calls to default to default Mode.

This fixes the situation where calling e.g. .effect("highlight")
was a no-op as if .show("highlight") was called.

Author: mikesherov

ui/effect.js

@@ -1256,7 +1256,7 @@ $.fn.extend({
 			effectPrefilter = function() {
 
 				var el = $( this ),
-					normalizedMode = $.effects.mode( el, mode );
+					normalizedMode = $.effects.mode( el, mode ) || defaultMode;
 
 				// save effect mode for later use,
 				// we can't just call $.effects.mode again later,
@@ -1275,7 +1275,7 @@ $.fn.extend({
 			},
 			queue = args.queue,
 			complete = args.complete,
-			mode = args.mode || defaultMode;
+			mode = args.mode;
 
 		if ( $.fx.off || !effectMethod ) {
 			// delegate to the original method (e.g., .show()) if possible