CODE: cache connection is_transfer value
signigicant speeduo for routesearch


git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6854 8aca7d54-2c30-db11-9de9-000461428c89
remove redundant/wrong png_start_read_image call

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6855 8aca7d54-2c30-db11-9de9-000461428c89
CODE: add class karte_ptr_t to carry pointer to single instance of world

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6856 8aca7d54-2c30-db11-9de9-000461428c89
remove outdated comment

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6857 8aca7d54-2c30-db11-9de9-000461428c89
FIX: no lighthouses at the edge of the map

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6858 8aca7d54-2c30-db11-9de9-000461428c89
CODE: check building sites for factories in fabrikbauer

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6859 8aca7d54-2c30-db11-9de9-000461428c89