Check if object is a jQuery object
<p>Is there a fast way of checking if an object is a jQuery object or a native javascript object?</p>

<p>example:</p>

<pre><code>var o = {};
var e = $('#element');

function doStuff(o) {
    if (o.selector) {
        console.log('object is jQuery');
    }
}

doStuff(o);
doStuff(e);
</code></pre>

<p>obviously, the code above works but it's not safe. You could potentially add a selector key to the <code>o</code> and get the same result. Is ther a better way of making sure that the object actually is a jQuery object?</p>

<p>Something in the line of <code>(typeof obj == 'jquery')</code></p>
