Support embedding collections/searches

[eyeseast]

Here's what the embed code looks like:

<div id="DC-search-group-homicide-watch" class="DC-search-container"></div>
<script src="//s3.amazonaws.com/s3.documentcloud.org/embed/loader.js"></script>
<script>
 dc.embed.load('http://www.documentcloud.org/search/embed/', {
 q: "group: homicide-watch",
 container: "#DC-search-group-homicide-watch",
 title: "Homicide Watch DC",
 order: "title",
 per_page: 12,
 search_bar: true,
 organization: 170
 });
</script>

[reefdog]

Renaming this to "Support embedding collections/searches", since it's actually going to use the same shortcode.