Start a new development version 0.2.11
Rename floor groups and tweak combat arena
Make RollDeep abstract
Make RollDiceXY more precise
Overhaul dungeon place generation

in particular, reducing FFloor fence depth.
Permit single-point rooms
Make it possible to specify max room size for a cave kind
Tweak caves content
Try hard to position skirmish opponents far away
Avoid corridors adjacent to rooms with FFloor fence
Avoid empty rooms that are not dug out (via corridors)
Use RND seed from previous game

Now, if dungeon generation crashes, it crashes the same on next execution,
and we can debug easily. TODO: refactor and clean up.
Fix trucating places by digging them in too small areas
Let corridors start at corners of places with FFloor fence
Ensure corridors don't touch FFloor fence

unless there is no space left, but even then sometimes
the corridors merge with the fence instead of touching
(TODO: make them merge always in such cases).
Make the Area type abstract
Move the Area module
Make void room choice safer

so that, e.g, initial actors and items fit in rooms.
Fix test

in the case of a monster killed in the first turn.
Then sending a '.' is not enough, because the messages
have to be cleared with a ' ' first.