RFC: Drop PPC support

[Sean Farley]

Takeshi Enomoto writes:

>> Historically we officially support the current and previous Mac OS X release (while not doing anything to on-purpose break older releases / being willing to accept patches to make things work on older releases).
>
> If we are not going to change this policy,
> PPC is no longer supported.
> It is up to the maintainers or the port.
> We don't have to remove what are still available for PPC.
>
> Personally I still use a big-endian Power Mac and try to maintain some ports
> as far as I can.

I think that's fine but as a policy (meaning: written as a FAQ or a
documentation of some kind) the first answer for PPC tickets should be:
you're on your own.

If a macports dev wants to help out personally, then sure, go for it.