Fix v2 data upload to swift

An upload of image data via the v2 api when using a swift backend would
stacktrace with 'UnsupportedOperation: seek'.

Wrap the data in a CooperativeReader to both 1) fix this issue and 2) reap
the multi-threaded 'sheduling fairness' benefit of the CooperativeReader.

Fix for bug 1147231.

Change-Id: I604c67d2d6ecd77a12e11b2f641edb4095c4bb60
Ensure disk_ and container_format during upload

This patch changes the image domain model so that the transition from
'queued' to 'saving' or 'active' status cannot take place if the image's
disk_format or container_format are not set.

Fixes bug 1131994

Change-Id: I454d9df736edd771f9d5d93eca4cd317116cc985
Merge "Fix v2 data upload to swift"