FIX: do not draw border of active window always as dirty

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6479 8aca7d54-2c30-db11-9de9-000461428c89
FIX: remove some calls to welt->set_dirty, reset dirty flag for toolbars

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6480 8aca7d54-2c30-db11-9de9-000461428c89