Re-raise exceptions in upload-to-image

This patch catches any exceptions returned from Glance during an
upload-to-image operation and re-raises them so that the user can see
the failure message and make the appropriate adjustments.  More
specifically, this addresses an invalid container format.

For example, the following command:

    $ cinder upload-to-image --container-format foobar ...

Goes from:

    ERROR: The server could not comply with the request since it is
           either malformed or otherwise incorrect. (HTTP 400)
           (Request-ID: req-f19bad2f-c39d-40a2-a3cc-6db9b9fe64cd)

To:

    ERROR: 400 Bad Request
    Invalid container format 'foobar' for image.
        (HTTP 400) (HTTP 400)
        (Request-ID: req-47cb2772-78c4-48b7-87ce-fb124ecfa989)

Closes-Bug: #1308689
Change-Id: If18851e0b9f5c242f84b1eab928b42d809335d80
Merge "Re-raise exceptions in upload-to-image"