Changing use of jaba.util classes to different method as cannot use these according to spec + changing various code as had equated connectedness with openness.

Before had connected site to all neighbours, open and blocked, when opening, and assumed site is open if connected to all neighbours. This is invalid as site could be blocked yet connected to all neighbours, and also by connecting site to all neighbours when opening would end up with percolation through blocked sites connected to open sites. Changed so openness and connectedness tracked separately and when opening a site only connect it with its open neighbours.