Walls aren't saved to file (LITS, Star Battle, ...)

[robx]

Rooms are saved to file as room ids of cells, and walls are reconstructed as the borders between these. That means that dead end walls or walls that separate a room from itself won't be saved.

This makes file saving and board duplication a bit useless while editing.

[robx]

Might be fixed by using encodeBorderQues instead of encodeAreaRoom, and bumping filever for those types.