Adds basic PA 404 handling

Render Rails default 404 page if a given PA doesn't exit
Merge branch 'master' into 404-redirect

* master: (73 commits)
  fix import_tools test
  put start monit in right place during deploy
  don't bring down the sidekiq webadmin with turnout
  fixes in import_tools
  remove custom whenever command during deploy
  Update binstubs for rails 4
  add on roles clause to monit restart in capistrano
  add sidekiq initialiser to set custom redis url
  use REDIS_URL env variable in staging too
  remove unused/non-present variables in redis.conf
  move redis_password in all vault
  remove if's in redis.conf template and unused settings
  Remove unnecessary jinja block
  monit handles sidekiq with init.d script, not service
  Use ansible user for sidekiq scripts, rather than hard coded
  Run unicorn as the ansible user, otherwise it won't work
  Run correct unicorn command
  add monit config for sidekiq
  Remove unnecessary jinja blocks
  Monit tasks for memcached and unicorn
  ...
Updates ansible scripts

* Removes unneeded host vars
* Ignore Unicorn boot errors (first Ansible run will fail to start
  Unicorn as the app won't be deployed at that point)
* nginx can handle more connections
Request assets from CDN in production
Merge pull request #135 from unepwcmc/cdn

Request assets from CDN in production
Removes db structure

There's no need for it to exist. It only causes commit/merge issues, and
is regenerated all the time anyway. We never load the db from schema,
only from migrations or dumped DBs.
Merge pull request #136 from unepwcmc/remove-db-structure

Removes db structure
Enables caching on search pages

Search results do not change between WDPA releases (and the cache is
emptied when releases are imported), so we can actually cache them and
not worry about stale data.
Merge branch 'master' of github.com:unepwcmc/ProtectedPlanet
Merge pull request #137 from unepwcmc/cache-search-results

Enables caching on search pages
Merge pull request #132 from unepwcmc/404-redirect

404 page
Updates lazy seeds to remove structure of DB

Including the DB structure (unsurprisingly) causes conflicts with
migrations etc, so we'll just inclue the seed data we need.
Merge pull request #138 from unepwcmc/dev-import

Updates lazy seeds to remove structure of DB
refactor sidekiq service template and make idempotent
Revert "add Devise and User model"

This reverts commit da8eb4c09d49efb824c76940b516f76b2539a7af.
Merge pull request #139 from unepwcmc/fix-sidekiq-ansible-script

Fix sidekiq ansible script
update monit check for sidekiq, removed pointless prefix
Updates production server details

alpha.pp.net is now pointing to a load balancer, so we must SSH to the
machines behind the LB.
Render correct 404 page
Make stats page show no stats, instead of erroring

If a model has no stats, show the page with zeros, rather than throwing
an unhelpful error.