CHeck for timeouts during file transfers

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7183 8aca7d54-2c30-db11-9de9-000461428c89
correct comments identation

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7184 8aca7d54-2c30-db11-9de9-000461428c89
CODE: make methods protected, correct comment

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7185 8aca7d54-2c30-db11-9de9-000461428c89
CODE: remove unused member gui_image_t::size_mode

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7186 8aca7d54-2c30-db11-9de9-000461428c89