use getDefaultGroup() in DemoData instead of hard coded 'Users'
[tine20] / tests /
drwxr-xr-x   ..
drwxr-xr-x - jmeter
drwxr-xr-x - js_client
drwxr-xr-x - ldap
drwxr-xr-x - setup
drwxr-xr-x - sikuli
drwxr-xr-x - tine20