(Not) deprecating py35 subports

[Mojca Miklavec]

Hi,

Recently a PR has been merged which put a py35 subport into a graveyard.

I just wanted to say that we should first focus our efforts into:
* Getting entirely rid of python 2.6 and python3.3 and lower, starting
with regular ports like vim which still ships with python26 and
python33 variants (but is by far not the only one doing so).
* EOL for 3.4 is less than one year from now, so we could just as well
start moving 3.4 to the graveyard, but it needs to be done in a
consistent way rather than randomly.

I would suggest not to put 3.5 to graveyard just yet. On top of that
our py-graveyard has a slight flaw. It replaces 3.3 and lower with
3.4, it replaces 3.4 with 3.5 and 3.5 with 3.6.

This means that if someone now deprecates 33 34 35 all at once, a user
with py33 subport installed would see three redirects (replaced_by)
until it hits py36. That's most likely not really desired. The default
replacement should be 36.

The whole idea of the graveyard was to help users migrate to a newer
version automatically, but in case of python it doesn't really serve
the purpose if ports get moved to the graveyard at random times (ok,
it makes sure that ports don't end up being installed forever, but the
replaced_by part is not really all that helpful).

Mojca