inArray搜索数组中指定值并返回它的索引（如果没有找到则返回-1)

$$.inArray(element, array, [fromIndex])
$$.inArray("abc",["bcd","abc","edf","aaa"]);
//=>1

$$.inArray("abc",["bcd","abc","edf","aaa"],1);
//=>1

$$.inArray("abc",["bcd","abc","edf","aaa"],2);
//=>-1
fix:isDocument
fix:低版本IE对indexOf方法的支持
fix:IE 对象不支持“forEach”属性或方法
fix:在IE中WCJ.fn.extend失效