erp5.zeo: Move variable-length crontab command to script.

When there are many ZODBs, this command can exceed crond's maximum 1024
bytes limit.
erp5.mariadb: Add convenience symlink to mysqlbinlog.
recipe.generic_zope_zeo_client: Simplify dict handling code.

Also, do not look unused options up.
erp5.zope: Simplify zope recipe parameters.

Remove non-needed parameters, empty unused parameter.
Move "inituser" closer to "user" and "password", as they are related.
erp5.erp5: Sort erp5.zope parameters for easier reading.