Got rid of DimensionPoint

I quickly bashed out a bunch of stuff, including making the new Point
class, before I realized I had two coordinate representations that had
identical sets of data.  Kbai DimensionalPoint
Actually finished removing DimensionPoint
Lots of work on ItemBlockPlacer

Particularly did stuff for its TIckHandler, the ItemBlockPlacerHandler.
It crashes immediately with an NPE of some sort, but at least it does
something.