sqapi: export ribi of ways

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6668 8aca7d54-2c30-db11-9de9-000461428c89
FIX: sqapi exporting of ways was pretty much broken

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6669 8aca7d54-2c30-db11-9de9-000461428c89
FIX: clipping region was wrong if tile is near lower border of screen - buildings shined through bridges

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6670 8aca7d54-2c30-db11-9de9-000461428c89
(An_dz/dwachs) translate comments

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6671 8aca7d54-2c30-db11-9de9-000461428c89
(An_dz) translate/improve comments

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6672 8aca7d54-2c30-db11-9de9-000461428c89
(An_dz) translate/improve comments

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6673 8aca7d54-2c30-db11-9de9-000461428c89
CODE: rename calc_akt_speed to calc_friction to reflect its purpose

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6674 8aca7d54-2c30-db11-9de9-000461428c89
Fixed documentation error.

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6675 8aca7d54-2c30-db11-9de9-000461428c89
add some const

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6676 8aca7d54-2c30-db11-9de9-000461428c89
.. and compile again

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6677 8aca7d54-2c30-db11-9de9-000461428c89
FIX: lower/raise tools check all affected tiles whether scenario allows terraforming them

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6678 8aca7d54-2c30-db11-9de9-000461428c89
FIX: overflow of progress bar when loading savegames

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6679 8aca7d54-2c30-db11-9de9-000461428c89
FIX: set world dirty when doing emergency zoom in

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6680 8aca7d54-2c30-db11-9de9-000461428c89
remove stray code

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6681 8aca7d54-2c30-db11-9de9-000461428c89
Small translation

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6682 8aca7d54-2c30-db11-9de9-000461428c89
Initial checkin of the sdl2 backend.

This creates a separate backend target except for some common cursor code.
It is based on work done in an earlier 'sdl2' branch, with help from
others on the Simutrans forum.