Many attempts at snap to grid.

Tried manual methods, plugins, etc and nothing seemed to stick. The way
I have it now sometimes works, buts its pretty inconsistent. I think
the snap to grid, which is part of dragend, is fighting with the force
simulator for control of the coordinates.
Another attempt at using JQuery UI tooltips. Doesn't work.

Still can't get JQuery UI tooltips to work and I have no idea why.