modifications where a TID can be given when starting a transaction. This is
necessary to support the copyTransactionsFrom() from BaseStorage and have a
better support of the ZODB API, where the tid parameter to tpc_begin() can 
be not None.


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@1005 71dcc9de-d417-0410-9af5-da40c76e7ee4