metastation update/bridge recolor/also fixes

ok
-fixes a floating sign and removes a sign that was on a window
-makes a few areas that were mis placed (solars omg) all fixed up
-puts a whole lot of contraband posters in maintenance and adds legit posters to library, security, meeting room
-adds boxstation's wall around the singularity for protection
-bridge recolored with dark tiles (pics in a jiff)
-is that it? probably some very minor fixes im forgetting about
merging of the map
fixes the two tiles
Merge pull request #5242 from quiltyquilty/metastationup-to-date

bringing metastation up to date/bridge update/fixes