fix bug - immovable objects include creatures. They can remove themselves from locations but a player can't
implement "kill the spy" mission - will change this later. This required a change to missions to catch where _object and _destination were both the same object. This would be the same for repair-type missions
add dialogue support to missions.
Note if there's dialogue on a mission, it won't be visible to a player through examine, only through talking to a creature. We don't yet have dialogue for artefacts.
track completed missions as a list of mission names, not just a count
add "show" and "read" as verbs
widen UI display
add a "bad" mission - player loses points
improve dialogue support around missions. Implement delivery of artefacts from successful missions
add cubicle and LotL article