FIX: properly unlock companies if they are created/removed in network games

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6382 8aca7d54-2c30-db11-9de9-000461428c89
FIX: correctly init mapcounter when removing company by nettool

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6383 8aca7d54-2c30-db11-9de9-000461428c89