The Hungarian stemmer should be ISO-8859-2 not -1

As reported by Tom Lane on snowball-discuss.  Fix from Olly Betts.

This commit includes the changes from
https://github.com/snowballstem/snowball/pull/4 and from
https://github.com/snowballstem/snowball-data/pull/2


git-svn-id: svn+userv://snowball.tartarus.org/snowball/trunk/snowball@585 633ccae0-01f4-0310-8c99-d3591da6f01f