FIX: only connect crossings by crossing-logic that have the same orientation

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7087 8aca7d54-2c30-db11-9de9-000461428c89
FIX crash when convoy has no vehicles after loading a savegame

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7088 8aca7d54-2c30-db11-9de9-000461428c89
Update same docu and a typo

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7089 8aca7d54-2c30-db11-9de9-000461428c89
Now just wait the longest loading time

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7090 8aca7d54-2c30-db11-9de9-000461428c89
Some more meaningful init of loading time

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7091 8aca7d54-2c30-db11-9de9-000461428c89