adds strict rule to jshint options (except for test files). "use strict" is added to the main jQuery closure and some "could-be-unsafe" this trickery in effects is silenced.

src/effects.js

@@ -233,6 +233,7 @@ jQuery.Animation = jQuery.extend( Animation, {
 });
 
 function defaultPrefilter( elem, props, opts ) {
+	/*jshint validthis:true */
 	var index, prop, value, length, dataShow, tween, hooks, oldfire,
 		anim = this,
 		style = elem.style,