FIX: errors with grid, water and artificial slopes

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6655 8aca7d54-2c30-db11-9de9-000461428c89
ADD: capacity, cost and maintenance can be set for each station building

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6656 8aca7d54-2c30-db11-9de9-000461428c89