Use of a common class "Building" to share code between Room and Trap
Range fighters wrong behaviour when attacking rooms
fixes #199
Crash when quitting game with creatures in hand
fixes #210
Merge pull request #212 from hwoarangmy/development

Shared common code between rooms & traps + crash when quitting game with creatures in hand + fixed range fighters buggy behaviour
Chickens spawn in tile 0,0 and then go through everything to their hatchery
Workers can claim tiles next to a claimed wall even if no claimed ground tile neighboor
Add support to sell rooms/traps
After selecting a tile, it is not possible to pickup a creature
Merge pull request #219 from hwoarangmy/development

Add support to sell rooms/traps + chicken spawn problem
Added the Hammock for Adventurers.

Fixes #218

I also updated the credits file and fixed a few things there.