Fix reversed method references

According to docs on kombu.serialization.register the params order is (name, encoder, decoder, content_type, content_encoding). This caused us a bit of grief as I was too lazy to read the actual docs on register() :)
344 - added the skip decorator to three tests.

Three tests were missing the @skip_if_not_module('redis') decorator.

https://github.com/celery/kombu/issues/344
Adds Randy Barlow to AUTHORS
epoll unregister catches fileno TypeError
Adds Tobias Schottdorf to AUTHORS
Extra check for #342
kombu[librabbitmq] now depends on librabbitmq 1.5.1
kombu[librabbitmq] now depends on librabbitmq 1.5.1
Bumps version to 3.0.16 and updates Changelog
Merge branch '3.0'