Fix bugs:

* Can't create categories and tags
	* Recursively create directories

dynastie/templates/add_category.html

@@ -1,7 +1,7 @@
 {% extends "base.html" %}
 
 {% block content %}
-<form action="/category/add" method="post">{% csrf_token %}
+<form action="/category/add/{{ blog.id }}" method="post">{% csrf_token %}
 {{ form.as_p }}
 <input type="submit" name="add" value="Add" />
 <input type="submit" name="cancel" value="Cancel" />