Change site and machine namespace to use continent name

- Used to be hub fullname previously which is not exported to the object
plenary, making impossible to locate the site template (not included
by default in the object plenary)
- Hosts must be rebuilt to use the new namespace

Fixes quattor#104

Change-Id: I71e59ffa750a264b88ecf35ae3e6ebecd73f98e2

lib/aquilon/worker/templates/city.py

@@ -30,7 +30,7 @@ class PlenaryCity(Plenary):
 
     @classmethod
     def template_name(cls, dbcity):
-        return "%s/%s/%s/config" % (cls.prefix, dbcity.hub.fullname.lower(),
+        return "%s/%s/%s/config" % (cls.prefix, dbcity.continent.name,
                                     dbcity.name)
 
     def body(self, lines):

lib/aquilon/worker/templates/machine.py

@@ -56,7 +56,7 @@ def get_rack_name(cls, dbmachine):
     @classmethod
     def template_name(cls, dbmachine):
         loc = dbmachine.location
-        return "%s/%s/%s/%s/%s" % (cls.prefix, loc.hub.fullname.lower(),
+        return "%s/%s/%s/%s/%s" % (cls.prefix, loc.continent.name,
                                    loc.building, cls.get_rack_name(dbmachine), dbmachine.label)
 
     def __init__(self, dbobj, **kwargs):