compile on linux again

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6820 8aca7d54-2c30-db11-9de9-000461428c89
FIX: climate and snowline gui limits

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6821 8aca7d54-2c30-db11-9de9-000461428c89