Added support for autoscale.
Merge pull request #175 from briancurtin/working

Cloud Monitoring Docs: Update with changes from Mike Asthalter.
Fixed style issues in the autoscale docs.
Merge branch 'working' of github.com:rackspace/pyrax into working
Updated version and release notes.
Updated the class docs
Add support for accepting UNIX timestamps

cloud_monitoring.get_metric_data_points operates on a start and end
timestamp, but previously the function was unable to directly receive a
UNIX timestamp value, only Python date/datetime or string-based
timestamps. utils.to_timestamp now returns numbers given to it, as
they're already timestamps. This change makes it work as the docstring
suggests.

Also added a comment to get_metric_data_points to explain the existing
conversion of UNIX timestamps to integers. The API currently times out
when given timestamps with fractional seconds.