Snowball 3.1.1 released

A new release is now available for download from:

https://snowballstem.org/download.html

The focus of this release is fixing bugs.  There are also some minor
optimisation improvement to the generated code.

You can view the full list of changes here:

https://raw.githubusercontent.com/snowballstem/snowball/v3.1.1/NEWS

A big thanks to those who've contributed to this release - in no
particular order (and apologies to anyone I've overlooked):

    Jerry James, Dmitry Shachnev

Cheers,
    Olly