Additional image member information

Return the created_at and updated_at values for image member.

Related to bp glance-api-v2-image-sharing

Change-Id: I50f514c8680d1299d41c107c993e7ee2b0d7a185
Avoid dangling partial image on size/checksum mismatch

Fixes bug 1122299

Previously, when the supplied image size or checksum didn't match
the calculated values, partial image image data was left dangling
in the backend store.

Now, we clean up when the mismatch is detected.

Change-Id: I916d78ef3b2065e87df31ec4fb405915417d68aa
Merge "Additional image member information"
Merge "Avoid dangling partial image on size/checksum mismatch"