Currently clients can not distinguish between non existing accounts
(which can be created) and accounts marked for deletion, which has
not yet been reaped and therefore cannot be re-created until reaped.
Following this patch, if an account is marked as deleted but hasn't
been reaped and is still on disk, responses will include a status
header:
'X-Account-Status' = 'Deleted'
Fixes:Bug #1188609
Change-Id: Ibd39965ae3f5d45fd78f130e0e31f5a0141a8633
8226761889