RabbitMQ stuff

- Sneakers config
- Rake task to perform work (sneakers:work)
- Retry config

Setup retry and dead letter queue
Pdf background generation & associates pdf with a given claim model
rewrote JS to be more cross-browser/robust
Merge pull request #437 from ministryofjustice/feature/claim-assosciated-pdf

Claim Assosciated pdf
- Don’t be tricky and use double bitwise not operator when Math.floor can be used.
- Initialise the prompt with the time to avoid having it in the locale file.
- Initialise the prompt with he time so when it is re displayed it immediately shows the correct timeout left.
- Isolate millis to second conversion only where it is required(updating the time left function).
- Suffix header in locale with _html
Merge pull request #444 from ministryofjustice/ui/selected-checkboxes

rewrote JS to be more cross-browser/robust
Merge pull request #426 from ministryofjustice/fix/session-prompt-redisplay-bug

Session Prompt Redisplay Bugfix
Merge pull request #442 from ministryofjustice/enhancement/rabbit-mq

RabbitMQ stuff
Ruby 2.1.5 and Rails 4.2.0.rc1