Sewer Conduit (openforge 2.0 compatible)

Hi Folks!

I decided to go along and add some stuff to the sewers. Since all of my remixes are based on 2x2 tiles, you couldn't build a single "sluice corridor" or conduit if you will, where the walls directly blend into the sluice. So I made these Walltiles, Connector Tiles and T-Crossings, that will give you the options to do just that. I also included barred tiles, to close the corridor up, if you want to. Be aware, that just like the other sewer tiles, the sluices are quite thin, in order