- st_key, st_floppy: avoid accidential actor shattering on door passages
- add attribute "secure", default "true" in Enigma mode, "false" otherwise
- do not toggle in secure mode when hit by an actor that is located on one
the target grids
- it_key, st_key: make key code visible
- add attribute "invisible", default "true"
- a visible key will show its code while being part of the inventory
- a visible key stone will show its code directly
- visibility is inherited:
- once a visible key is plugged into an invisible key stone, the stone
becomes visible
- once an invisible key is plugged into a visible key stone, the key
becomes visible when reinserted into the inventory
Note:
- images for visible key items and stones are still missing
- secure key and floppy stones do not keep callback functions from closing
doors on actor positions.
