Do not call meta.SetStored().
Fix the signature of SetStored.
Add a doc comment.
Adjust to further changes in {utils}/filestorage.
Move interface checks into a test file.
Adjust a doc comment.
Dereference values consistently.
Clarify an error message.
Test against a fake backups storage.
Adjust to metadata changes.
Set the resulting metadata ID after creating a backup.
Revert "tools tarballs now live in a directory named after their stream"
fix broken compile
Merge pull request #981 from natefinch/revert-968

Revert 968

This reverts PR #968, by request of QA (fixes bug https://bugs.launchpad.net/juju-core/+bug/1386766).  It is just a revert plus a tiny change to fix a test added after this change that became incompatible after the revert.
Update utils repo dependency.
Add HTTP request helpers to the API client.
Drop a superfluous error return.
Add some doc comments.
Fix up a few error messages.
Use path.Join instead of fmt.Sprintf.