added ability to search by author display name

Here's an implementation for allowing users to search by display name.
Wordpress doesn't have a great way of hooking into a display name
change, so I had to hook into edit_user_profile_update and
personal_options_update then retireve the POST var from the form. This
isn't a great way of doing things, but since those 2 hooks fire before
the author is updated it's the only way to get the new display name.
Update Searcher.php

ability to update query args
faceting api changes, support for range faceting
fix for #4
Merge branch 'master' of github.com:parisholley/wordpress-fantastic-elasticsearch
don't break if ranges aren't defiend
update version
merged conflicts