Doors between rooms are not "shared"

[Syndaryl]

There's two related problems here:

• When two rooms are adjacent, both rooms may knock doors into the wall between them. This increases the number of doors in a wall shared with two rooms to approximately twice the intended value
• Each room only manages the list of doors it opened, and does not know about doors opened by other rooms into its area, even though to a human that door is clearly part of both areas.

This results in a) a funny number of doors that b) are inevitably not completely described

EDIT:

• [ ] Create central door registry (include door object, and co-ordinates)
• [ ] move door creation to a separate pass after room creation
• [ ] door creation needs to check the registry to ensure no conflict
• [ ] write a method to determine if a room wall is shared with another room
• [ ] door creation needs to inform the room on the other side of the wall

[Syndaryl]

Probably related to #61 - the solution for one should help with the other anyways.

[Syndaryl]

Additional issue is that the two rooms may knock a door through the same grid position

[Syndaryl]

The many door issues I think are best handled by pulling door code out of the room generation. Have a door pass after creating all the rooms. Create a central door registry to check against to prevent "overlap" as part of this.