[bug] Node ports of HTML tables are ignored

[martinrieder]

I tried to apply this script to the WireViz output files, that are generated using Graphviz. These contain a lot of nodes with HTML tables which are not properly recognized. When clicking one of these, the corresonding edges are not highlighted as they should.

Please check with one of the example files from here:
https://github.com/wireviz/WireViz/tree/master/examples

[martinrieder]

I confirm that PR #4 fixes this. Many thanks @Thierry61 for your contribution!

I am leaving this issue open until the PR is merged.