Ported the MiniStation branch.

MiniStation is now a single folder which isn't included by default. When you tick the code file for the ministation map, like with tgstation and metastation, it will then include the necessary code files itself. These code files modify certain datums, like jobs, supply packs and uplink datums.

The modified files outside the MiniStation folder are modifications made by the MiniStation branch which aren't changes exclusive to MiniStation.

Such as changing the unused circulator, which only MiniStation used, so that it was fixed and would correctly match the direction of the thermal generator.
The TEG was also changed to have a better interface and to include the above fix.
The department security was changed so it wouldn't runtime if it didn't find a checkpoint.
The preferences' SetChoices was changed so that the screen would automatically grow for every column in the job list.

The main difference between this version and the forked version is that the Unemployed and the Lieutenant was reverted back to their original names; since it would've been a massive pain to add support for that.
Adding a missing file.
Added more signs and different styles of floor tiles to the map.
Merge pull request #2546 from Giacom/MiniStation

Ported the MiniStation branch.