Make icons searchable

I hadn't realized other people had already done this (and had open pull requests), however I'm submitting mine anyway as well because it's different enough.

My biggest problem with FA is finding icons that are named differently that what I'm thinking. This pull request adds a bunch of metadata to each icon that it can be filtered on. I was having a lot of trouble finding certain icons (such as "close" which is actually "fa-times", or "like" which is actually "fa-thumbs-o-up"). So, this adds a ton of keywords that can be filtered on.

Here's a demo:

http://gkoberger.github.io/Font-Awesome/icons/

Try searching for "forward", "location", "settings" or "close".