Merge simplified UI, fixes #481
bump version
use protocol-relative urls, fixes #502
MSG -> JID
Update Celluloid API usage, use .async, fixes #500
Allow access to the JID via #jid, fixes #496
cleanup
complex -> simple
Use a regular object instead of a mock for exception data

This test doesn't assert anything about the test data itself. Therefore
using a regular object is fine.

This also fixes the build for Rubinius. The problem is that a minitest
mock object removes all kinds of methods that should be there. Since
exception_data is for example used in an array later on, it should
respond to methods like equal? and == in order to be able to behave
properly in an array.

In MRI you can get away with this, because once you go into C land, you
don't go back to Ruby until you're done. This means you can remove
methods that data structures normally depend on without MRI breaking.
Merge pull request #504 from dbussink/master

Use regular object for exception data
Support for strictly ordered queues in config
Merge pull request #507 from brainopia/master

Support for strictly ordered queues in config
Add delay_until extension method
Upgrade to minitest 4
fix retry option on normalize
Merge pull request #511 from elpic/master

Fix retry on normalize_item method
Update test descriptions
Don't clear workers set until actually shutting down, #492
Fix retry off by one, #512
Allow rbx 1.9 mode to fail on Travis