Nodes should gravitate toward a coarse grid

[dondi]

This will probably require getting underneath the force layout algorithm.

[dondi]

General grid size: twice the width of a node horizontally, twice the height vertically.

[dondi]

Change grid size recommendation: just do node dimensions + fixed margin. Make sure to include a "Snap to Grid" option so this can be turned on or off.

[britainjs]

Tried several approaches to this, but I can't seem to get the initial grid to stick. I left the attempts in as comments.

[kdahlquist]

As per discussion this morning in our f2f meeting, we are going to punt this completely. The manual "snap to grid" is replacing this and even that has been moved to priority 4.