Adds a maze generator

Created by: unid15

More of a proof-of-concept but still very usable. It lets you customize its size, wall and floor types. You can also enable dynamic lightning in it to make it more fun. Max size is 200x200

Use it by spawning /datum/map_element/customizable/maze. No exit or entrance is generated - you have toplace one yourself

Featuring the recursive division method: https://en.wikipedia.org/wiki/Maze_generation_algorithm#Recursive_division_method

GALLERY: (gifs are outdated)