Hi

I had a graph with about 20 vertices and about 100K edges. When I run the dot command I get the following error messages regarding the size of the graph and then a 16MB PNG is generated which I can not zoom into that to get information.

```
>dot -T png my_dot.txt -o my_dot.png
Error: Edge length 88795.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
Error: Edge length 93134.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
Error: Edge length 92711.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
Error: Edge length 93134.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
Error: Edge length 66125.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
Error: Edge length 66125.000000 larger than maximum 65535 allowed.
Check for overwide node(s).
dot: graph is too large for cairo-renderer bitmaps. Scaling by 0.0484215 to fit
```

The output is shown in the picture.

Is there any way to better show that graph? I mean interactive behavior for zooming in or out?