ZMySQLDA connector for the activities database would finish its
commit procedure before ZODB, making the description of an activity
message in MySQL available before its respective data in the ZODB.

The fix consisted in replacing the ZMySQLDA connector with another
one based on ZMySQLDA but with a “sortKey()” method that forced it
to be sorted after both the ZODB connection and the ZMySQLDA
connection for ZSQLCatalog.

Analysis of issue was done by Sebastien and Julien.

This patch itself was done by Leonardo.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@41598 20353a03-c40f-0410-a6d1-a30d3c3de9de