Add pan and zoom functionality to the topology graph
Add zooming and panning functionality to the topology graph. Also the page rememberes
the old setting of the graph position and size. So, after refreshing the graph has
the same position and size as it had before.
https://fedorahosted.org/freeipa/ticket/5502
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>