Allow streams version to be parameterised so that it can be different for images and tools metadata
implemented the sender worker for metrics
added test and comments after first round of reviews
second round of of review, support bulk calls in setting sent,
added more mocking in tests
support bulk calls in the sendmetrics api call
updates after merging with trunk
Added new status format option: oneline to list units & their subordinates.
Revert "Added new status format option: oneline to list units & their subordinates."

This reverts commit 6841d5c80f68bbfc36da088f2d9c987300c64b1f.
Merge branch 'master' of https://github.com/juju/juju
Added new status format option: oneline to list units & their subordinates.
Added expected request parameter to PatchUnitResponse function.
added the environment uuid to the metric batch
uuid -> UUID
Add the API client side for backups.
Move backups into its own package.
Migrated formatter to its own file. Refactoring.
Merge branch 'master' of https://github.com/juju/juju
Changes from 3rd round of reviews
Merge pull request #736 from ericsnowcurrently/backups-apiclient

Add the API client side for backups.

Note that backups has its own facade, so it isn't quite as simple as adding a new method on Client.
Tweak streams versions constants
Merge pull request #745 from wallyworld/tools-simplestreams-v2

Allow streams version to be parameterised so that it can be different for tools and images

This started out as a branch to use "v2" simplestreams metadata for tools to allow different metadata for 1.20 and newer vs 1.18 and older version of Juju. The fix is to change how simplestreams paths are resolved such that the streams version is now parameterised.

A different direction was decided on, but this change is still useful because it simplifies how Fetch() is invoked, provided a cleaner implementation of path resolution, and allows for easy changes of the streams versions in the future when needed. The changes are mechanical.