* makes ore silo connecting work on multi-z
* I merged the two checks for same z level when connecting an ore silo, and disconnecting it. This was because I didn't want to copy paste the code to use it twice, which was what now caused the problem of multi-z maps being unable to connect ore silos on the same level. At the time it was also intentional since it's easier to connect than to disconnect something, but I realize that this inconsistency isn't great or beneficial to anyone.
* Turns it into a helper instead
John Willard
9f5e3118bb