Store deadlocks might happen when the order in which storage nodes receive
object data (and hence, grant write lock for those objects) is not
consistent among clients. So when a store timeouts, it might be because
another transaction got the store lock on this storage and object, while
it might wait for locks we got on other storage nodes or objects.
In doubt, report a conflict to abort current transaction in hope for the
other transaction to succeed.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2109 71dcc9de-d417-0410-9af5-da40c76e7ee4