non-jQuery equivalent of :visible in JavaScript?
<p>So jQuery provides this awesome pseudo to query in DOM on ':visible', unfortunately, its rather heavily tied into the core of jQuery and Sizzle (or whatever engine you may use).  Is there a good equivalent in plain JavaScript when only a given element is known?</p>

<p>A reminder on the jQuery :visible rules:</p>

<ul>
<li>They have a CSS display value of none.</li>
<li>They are form elements with type="hidden".</li>
<li>Their width and height are explicitly set to 0.</li>
</ul>

<p>An ancestor element is hidden, so the element is not shown on the page.</p>

<p>Note: checking just style of the given element will not always work: a parent might be hidden instead hiding all children.</p>
