[DO NOT MERGE YET] Engineering Substations

DO NOT MERGE YET!

Point of this update is to add Engineering Substations.
Substations are rooms which supply power to certain parts of the station. They are useful for load balancing and advanced power control. I also plan to expand them to house atmospherics controls too, which allow you to manually alter atmosphere in certain areas (such as, burning department flooding waste loop? Close valve and separate it! Intruders in science? Connect N2O canister, close distro valve and open vents. Good night!)
Substations are planned for:

Engineering (Atmos, engineering itself, etc. Probably will be joined with main SMES room).
Medical (Well, medbay...)
Science (Probably in same room as medbay substation)
Civilian(Garden, chapel, kitchen, bar, dorms, etc.)
Command (central station section. This includes the AI [AI will still keep it's SMES, but i plan to nerf it a bit so it's not infinite power supply now.])
Security (Brig and adjacent security areas)

Some areas will be still connected directly into the main grid. This is both for technical reasons and balance reasons. For example, hallways won't take power from substations.

Each substation will also have small SMES type power storage (thinking about PSUs?) for balancing. I don't expect it to have large capacity. (1M charge when compared to 5M of regular SMES?)

This update will also include buildable SMES, if vote on the forum passes.
http://baystation12.net/forums/viewtopic.php?f=5&t=11144

Right now it seems 91% voted Yes.
minor thing, there is visible_message proc that can be used to avoid writing this loop everwyhere.