- renaming to st_actorimpulse, st_actorimpulse_invisible
- new attribute "invisible"
- attribute "force" renamed to standard attribute "strength"
- global attribute "BumperForce" renamed to "BumperStrength"
- invisible actorimpulse are visible with glasses with SPOT_ACTORIMPULSE
- boulder stones are reflected on actorimpulse
- it_glasses_broken as it_glasses in state SPOT_NOTHING = 0
- Clusterstones: fix problems with reengineered neighbor stones - switch
completly to new methods, avoid usage of obsolete get_kind()