[ppml] Use of HD ratios (esp. 0.94)

[michael.dillon at bt.com]

> In terms of allocation efficiency, and utilization requirements, using
> HD-56 instead of some other kind of HD, unfairly penalizes 
> those who act as good "Internet citizens", and allocate 
> longer prefixes to customers.

Those are BAD Internet citizens who are not following the basic
architecture of IPv6 which attempts to give each level of allocation,
more addresses than they could ever need. /48 does that for end user
networks, and it can be argued that /56 maintains that for residential
end users.

--Michael Dillon