Add 'compatible only' search option

[chowse]

Page:
http://chowse.github.com/amo-redux/search.html

Add a checkbox that, when checked, filters search results to only those that are compatible with the browser being used. This would be the equivalent of setting the 'Platform' and 'Firefox Versions' based on the visitor's user agent.

If the user is not using Firefox, this option is omitted.