Include cell name in event filename template
Include cell name in event filename template

For larger deployments, the region name should be parameterized too.

Change-Id: Iac7e589c4b58a74b5730a436a77cac31d7fc1fe1

madkiss/stacktach-sandbox,madkiss/stacktach-sandbox,madkiss/stacktach-sandbox,stackforge/stacktach-sandbox,stackforge/stacktach-sandbox,openstack/stacktach-sandbox,openstack/stacktach-sandbox,openstack/stacktach-sandbox,stackforge/stacktach-sandbox