[WIP] Z-level splitting

Initial commit for Z-level splitting, feel free to assist if you feel like it by making MR's to my zlevelmodify branch on my fork.

Warning: You cannot compile due to compilation errors

Warning: You cannot open any of the maps due to compilation errors

Before my changes, this is how the maps were laid out:

z1	Box	Deff	Taxi	Meta
z2	box_centcomm	deff_centcomm	taxi_centcomm	meta_centcomm
z3	oldtcommsat	guardedtcommsat	rewardlesstcommsat	rewardlesstcommsat
z4	ruskiederelict	ruskiederelict	taxiderelict	ruskiederelict
z5	bigroid	smallroid	spidership	crackedroid
z6	spidership	spidership	squidroid	empty

Todo:

• Fix the compile errors. This has everything from voting errors to map define errors.

• Add a system to allow for randomly picking a z-level from the folder for that z-level (except for centcomm)

• Make every non z1/z2 have taxi support for derelicts and the like.

• Make every non z1/z2 have identical tags for non taxi shuttles to point to. Examples being the nuke shuttle and mining shuttle.

• Shame the people who didn't add the goonecode to the rewardlesstcommsat (I'm leaving it like that too)

Also I moved unused maps to unused folder, and renamed boxstation to boxstation from tgstation.