Update dennis to v0.4.3

This picks up a couple of new rules and fixes a warning rule that wasn't
working right.
Remove puppet scripts; add scripts/ directory

* We don't use puppet for vagrant, so we can remove all these puppet
  things.
* Add scripts/ directory. Going to start putting runscripts in here.
[bug 1047681] Fix mlt call to be more resilient

Previously, if the MLT call failed for a response, we would kick up an
HTTP 500 error and not show the response. That wouldn't be a big deal
except it turns out there are a myriad of reasons it could fail.

This makes that code more resilient. If it fails, we'll display a very
ugly looking error instead of failing completely. This makes that view
usable when ES is down as well as if the response hasn't been indexed
(rabbitmq down, ES down, reindexing the site, ...).
[bug 948954] Redo index admin

* adds reindex command (different from "delete-and-reindex" command)
* adds list of outstanding tasks to top of page
* moves record history to bottom of page
[bug 1045623] Overhaul rate limiting and update limits

* reworks all the code so that we're using django-ratelimit as the core
  of our throttling instead of django-ratelimit for some things and
  django-rest-framework's throttling stuff for other things
* move throttling-related things from the feedback app to the base app
* change throttling from 100/h to 50/h for all posting (api and non-api)
* add throttling to the hb posting of 50/h
* add double-submit throttling to the api posting of 1/10m
* change double-submit throttling for non-api posting to 1/10m
Fold actual_ip into defaults