Require unique router names

[KenBarr]

Currently router names are: Primary, Backup, Monitor.
These names need to be uniquified to allow MNR between HA clusters.
Should be easy to find nodes in HA cluster in EC2 list and ref back to stack.

[KenBarr]

Router name and EC2 name are not related.
Issue#13 deals with EC2 seperately

[vkotheka]

Can be externalised in the template so that user can fill in the router name they want to use?

[vkotheka]

This feature is useful when somebody is using HA quick start template to deploy primary and DR site. However, with router name hardcoded in script, both primary and DR site router names are same and it complains while setting replication mate as the router name is same. The workaround I used was to manually change router names but that spoils the HA config group and require the set up to be done manually on triplet.