The most simple way to use this feature is to use --activity_node option only,
but it is also possible to:
- run only a ZEO server (--activity_node=0)
- run only ZEO clients
- run only activity nodes, by specifying no test
- specify HOST:PORT to listen/connect for ZEO storage and ZServer

Load/save of catalog is done by the process running the ZEO server.
Load of static files is done by all processes. Save of static files is done by
the process running unit test.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@35374 20353a03-c40f-0410-a6d1-a30d3c3de9de