FIX: checks for routing ways over bridges with conversion_factor 2

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6612 8aca7d54-2c30-db11-9de9-000461428c89
optimise - cache lookups to get_water_hgt

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6613 8aca7d54-2c30-db11-9de9-000461428c89
more get_water_hgt caching

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6614 8aca7d54-2c30-db11-9de9-000461428c89
FIX: play sound again

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6615 8aca7d54-2c30-db11-9de9-000461428c89
squelch integer comparison warnings

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6616 8aca7d54-2c30-db11-9de9-000461428c89
CODE: remove spurious assignment

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6617 8aca7d54-2c30-db11-9de9-000461428c89