Add support for pseudo-classes about stylebot

[ankit]

They work if you manually write the CSS selectors. You can do so by clicking on the CSS selector text in the panel which will show a textfield to write your own CSS selector.

[ankit]

I think you meant defining for own classes for elements. That would be useful, but will mean quite a bit of additional work. Maybe instead just use a lot of CSS hacking! :)

Closing issue for now.