Core DMAPI functions

This folder contains all DMAPI code not directly involved in an API.

_definitions.dm contains defines needed across DMAPI internals.
core.dm contains the implementations of the /world/proc/TgsXXX() procs. Many map directly to the /datum/tgs_api functions. It also contains the /datum selection and setup code.
datum.dm contains the /datum/tgs_api declarations that all APIs must implement.
tgs_version.dm contains the /datum/tgs_version definition