CLOUDSTACK-4405: add a tool: cloudstack-agent-upgrade to upgrade bridge name on kvm host
CLOUDSTACK-4528: [Vmware] new mapping vmware datacenter cloudstack zone - Virtual Router host migration across cluster FAIL

Changes:
- listHosts within same cluster for migration of system and router VMs
CLOUDSTACK-4528 [Vmware] new mapping vmware datacenter cloudstack zone - Virtual Router host migration across cluster FAIL

Change:
- Also add a check in migrateSystemVM API to check that source and destination host are in the same cluster
CLOUDSTACK-4089: UI > zone wizard > hypervisor VMware > physical network > vmware_network_label: remove trailing comma if there is any.
CLOUDSTACK-815. DOC. Fix Regions documentation for reviewer comments.