Adds network/cidr mapping into a new service property

Makes it possible to resolve network subnets within a service
template; the data is transported into a new property ServiceData
wired into every service which hopefully is generic enough to
be extended in the future and transport more data.

Data can be consumed in service templates to set config values
which need to know what is the subnet where a deamon operates (for
example the Ceph Public vs Cluster network).

Change-Id: I28e21c46f1ef609517175f7e7ee19e28d1c0cba2

puppet/services/neutron-midonet.yaml

@@ -4,6 +4,10 @@ description: >
   OpenStack Neutron Midonet plugin and services
 
 parameters:
+  ServiceData:
+    default: {}
+    description: Dictionary packing service data
+    type: json
   ServiceNetMap:
     default: {}
     description: Mapping of service_name -> network name. Typically set