drop python 2.6 (not supported by django any more)
switch from django-registration (dead and broken) to django-registration-redux, fix issue #116
remove south dependency (and south migrations)
create new initial migration with django's builtin migrations
update docs
this is esp. useful for v6 hosts, where your provider might give you a changing prefix (we assume /64), but your interface ids stay the same.
but same mechanism also principally works for v4 (we assume /29), except that you usually do not get a v4 network where the network address is changing.
and when it comes to dynamic addresses, many people only get 1 ipv4 address anyway. the related host could then be used for aliaseses with ifid == 0 for all aliases.
