adjust ES DSL for better category filtering on mobile
update:
- vhosts in-app.  the previous vhosting mechanism relied on webserver / additional uwsgi apps to provide vhosting.
  with this update, you can now do vhosting in a single uwsgi app / nginx vhost.

  just add in the additional vhosts in sever_name for nginx

  then, create the relevant config file in conf.d/

  www.vhost.com.json

  we expect this to load in json.loads()

  any values declared in here will override global defaults from config.py

  this allows you to create a vhost with different skins, mongo/ES offsets with no additional overhead

- this update displayed some thread safety issues that are hopefully eliminated.