Don't use for-in loops on Arrays. Fixes #7817. Thanks to dmethvin.

Conflicts:
	src/manipulation.js

test/unit/manipulation.js

@@ -1,5 +1,8 @@
 module("manipulation");
 
+// Ensure that an extended Array prototype doesn't break jQuery
+Array.prototype.arrayProtoFn = function(arg) { throw("arrayProtoFn should not be called"); };
+
 var bareObj = function(value) { return value; };
 var functionReturningObj = function(value) { return (function() { return value; }); };