area fixes and catwalk placement

fixed a few areas by actually adding them into proper places and removed areas that were for some reason in Space (why would you do this), replaced catwalks ontop of space instead of whatever the fuck they were. control+click, people. it's not hard.

oh, also placed plating underneath Security lobby windows since someone didn't know that's what you should do, and swapped out some airfilled plating outside of disposals with airless plating. I don't know who put that there, but I just saw it and it bothered me.