admin: Comment out activation url

The activation url is generated from the URLs that have been defined on
the astakos node. If the admin node is installed elsewhere, then the
URLs are useless.

Comment them out for now until we find a better solution.
admin: Remove hard-coded urls

Remove hard-coded urls from the admin templates and use the "{% url %}"
tag instead.
admin: Improve expensive query

Improve an expensive OR query by using the "IN" operator to search for
VM IDs in IP logs of user.
Merge branch 'feature-admin-fix-demo' into feature-admin
admin: Use admin as proxy of stats urls

Serve the stats of astakos and cyclades from the admin views. This is
done by importing the relevant functions from the astakos/cyclades
packages and providing the following URLs:

* (/admin)/stats/<component> and
* (/admin)/stats/detail/<component>

With this approach, we achieve the following two things:

a) The Javascript code will not have limitations due to the same-origin
   policy.
b) We can use the existing authorization methods to get the stats,
   without having to add the user to the 'admin-stats' group or sending
   an X-Auth-Token

The limitation of this approach however is that it cannot be used yet as
an API.
Merge branch 'feature-admin-charts' into feature-admin