[PATCH] traditional post-release doc text and release-check.sh updates

[David Bremner]

Tomi Ollila <tomi.ollila at iki.fi> writes:

> - added period to the end of the only 0.20.1 news item so that news2wiki
>   will not make it a header line

This part is trivial and fine.

>
> - changed copyright year to 2015 in doc/conf.py
>
> - made release-checks.sh to check copyright year in doc/conf.py

This part is less trivial, and should maybe be a patch by itself.

Is it just me or do we generally prefer $(foo bar fubz) to `foo bar
fubz`

>
> - made release-check.sh to execute python3 compatible version check code

It would be nice to say that the only change here is adding parens to
the print.