Refactor RateLimiter so that if Redis is not running, everything still runs normally (minus the rate limiting protection). My assumption that creating a Redis connection would throw an exception if Redis wasn't running was wrong. The exceptions actually occur when you issue a command. This is for #224.

{% load url from future %}
{% if show_button %}
<a href="{% url 'forums-edit_post' id=post.id %}"><img src="{{ STATIC_URL }}icons/page_edit.png" alt="Edit post" title="Edit post" /></a>
{% endif %}