Make possible to process more than one message per dequeueMessage call. This...

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