Rackspace-monitoring

* Make all the create, update and delete methods take an optional 'who' and
'why' keyword arguments.

* Update 'alarm history' endpoint. It has been renamed from 'alarm history'
to 'alarm notification history'.

* Don't error out if entity has no IP addresses.
[Caleb Groom]

* Make sure it works with Python 2.5 and 3

* Initial release.