Fixes issue with area power alerts, related to many space ruins using the same area and thus having multiple apcs in the same area with some wanting the area to be powered and some unpowered, leading to the area's power state constantly switching (area/procpoweralert() becoming the second most costly proc on the profile).
I fixed it by giving to many space ruins their own area (mostly those who have an APC).
Making a global list var "teleportbeacons" so we don't have to use "in world" to fing all tracking beacons used by teleporters.
Moved all main .dmm maps to _maps/map_files
Each main map gets a .dm file in _maps, this is what's ticked, -NOT- the .dmm file.
This allows use of a MAP_NAME define for various purposes, and lays the groundwork for map customization in the future.
Also included a hacky dm.sh script which supports swapping maps.
For example, "./dm.sh tgstation.dme -Mmetastation" would compile with metastation.
Signed-off-by: Mloc-Argent <colmohici@gmail.com>