Added catwalks and railings. Ported from Vorestation who ported them from Eris.
Note, catwalks can be placed on plating (as is seen on the vorestation map Tether) and is done so here as well. However it doesn't seem like it is possible to build said catwalks on plating. Did not bother to adjust this at this time. Something to sort in the future.
Adjusted SC station dmm to use both the railing and catwalks as well as a couple fixes for the floor tile adjustment in a earlier commit.
3e90725a45