Specify CIDR netmask for each VIP

Explicitly setting the netmask for each VIP works around a bug
in Pacemaker where an incorrect netmask is calculated. This
subsequently sets an incorrect broadcast address.

Change-Id: Icf208eff1be27765611500ae0e71ead122a7c4ce
Closes-bug: #1277614
Merge "Specify CIDR netmask for each VIP"