README

Issues during coding:

1) Why mouseout does not work on both cluster node and boundary?
Ans: When the user hover on the feature, which triggered the mouseover, the canvas redraw the the previous features go away.
    Thus when hover out, the system cannot find the previous corresponding object.

overlapping minimization module:	
2) [updated] need a way to simplify the curves when actually drawing on the line (after optimization).
3) may calculate the area/other attributes of the hulls before and after the optimization. If the diffrence is too significant, we may want to reject the changes, or do not display the hulls.
4) [done] In some cases, the line-center-based point shifting method may not work, since the new position can be the same as the old position due to specific polygon topology. Might make sense to think about changing both the parent and child hulls, not just changing the child. The idea of Force-Directed Layout makes sense in this case.