Autocreate cleanups

Autocreate was messy - now cleaned.
Auto-create now occurs at account POST, and container PUT only.
A method for autocreation was added
Autocreation was removed from account_info and container_info.

Fake-it as if the account exists on account HEAD and account GET.

Return 404 on everything else when the account does not exist.

Fix: Bug #1172223
Fix: Bug #1179140
Change-Id: Iac54c1438eb09883fbc29a1ad2ac2245b95efc92
Merge "Autocreate cleanups"