Infinite loop during packing

[hasanbalci]

I was trying to pack two disconnected nodes and realized that sometimes code runs into infinite loop. I think it's this loop in which the cells variable becomes 0 and cannot find placement. A sample case can be found here.

[ugurdogrusoz]

@hasanbalci Pls check

[hasanbalci]

In this sample case, I give the positions of edge's source and target nodes as the edge start and end points instead of using edge's bounding box since it's more convenient in my case. Packing either takes too much time or runs into infinite loop and I think it sticks around on this for loop.

[hasanbalci]

It's working now.