Make possible to process more than one message per dequeueMessage call. This factorises MySQL access cost which is rather high because of a sort occuring in the query. SQLQueue_readMessage will still return just one message by default, so behaviour will not change unless default number of fetched rows is increased in that ZSQLMethod.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@16505 20353a03-c40f-0410-a6d1-a30d3c3de9de