sqapi: add set/get traffic rate method

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6235 8aca7d54-2c30-db11-9de9-000461428c89
sqapi: add tool_set_traffic_level and forbid it by default

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6236 8aca7d54-2c30-db11-9de9-000461428c89
sqapi: allow all tools for public player

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6237 8aca7d54-2c30-db11-9de9-000461428c89
CHG: enable changing traffic rate in network games

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6238 8aca7d54-2c30-db11-9de9-000461428c89
sqapi-doc: add changelog

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6239 8aca7d54-2c30-db11-9de9-000461428c89
update squirrel-types

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6240 8aca7d54-2c30-db11-9de9-000461428c89
sqapi: consistently use traffic_level instead of traffic_rate

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6241 8aca7d54-2c30-db11-9de9-000461428c89
FIX: correctly initialize syncsteps for network games

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6242 8aca7d54-2c30-db11-9de9-000461428c89