- bridge floor - complete rewrite:
- rename to fl_bridge, fl_bridge_gc, fl_bridge_bw, fl_bridge_bn
- attribute flavor, values "gc" (grey centered), "bw" (brown from west),
"bn" (brown form north)
- full StateObject support: state attribute of OPEN, CLOSED
- default state is OPEN
- message "signal" now with values 0/1
- message "toggle" instead "openclose"
- stones not floating on bridges do fully close it - actors can pass
- snapshot principle: stones on bridges are evaluated on initialization
and on any set operation, closing the bridge according to the float feature
- fix Floor: do set attributes in class hierarchy - not directly on Object
- fix Window: do not shatter marbles on move
- change Puzzle: hollow puzzle is no longer floating - thus pressing triggers
and bridges, too
- fix level "Temple of Gold" - usage of bridge message "signal"