WIP Support for HTML labels

[clemens-tolboom]

There currently is no support for HTML table labels http://graphviz.org/content/node-shapes#html

I was curious for this support so wrote these small failing tests.

• [ ] Fix failing test for normal title (trivial to fix)
• [ ] Fix failing test for record title (is all escaping properly esp. ports: http://graphviz.org/content/node-shapes#record)
• [ ] Fix failing test for HTML title (this is tricky due to the current escaper)

Note I come from https://github.com/clue/graph-uml and https://github.com/clue/graph of which the latter has a graphviz rendering. The latter is about to split off graphviz into it's own project so maybe we can team-up ... not sure.

Feel free to close or fix for the tests :-)

[clemens-tolboom]

@alexandresalome is it worth adding support for this? I'm not sure I find the time for the fix due to related projects :-(

Anyway feedback is welcome :)

[alexandresalome]

We might introduce a BC break here to make it clear (about escaping or not):

• When a string is passed, escape it as "text". So if I provide markup for a table, it should be displayed as text if I provide it as text.
• Create objects RawText and extend them in Table (and maybe Record)

[alexandresalome]

Fixed in master. You can now disable escaping to get your table rendered.

I added an example here: https://github.com/alexandresalome/graphviz/blob/master/samples/02-table.php

I'll be releasing soon, probably next week. Before 1.1 is released, you can use dev-master

[clemens-tolboom]

Guess you haven't added the tests from this PR :-(

[alexandresalome]

@clemens-tolboom I added tests for unescaping feature