Configuration option to use - for generated HTML instead of _

It would be nice if there was a configuration option to use dashes instead of underscores when generating HTML ids and classes class="foo-bars" instead of class=foo_bars.

Many popular libraries such as Bootstrap and Foundation use dashes for their classes and it would be nice to have some consistency in our applications.

I apologize if this issue has been presented before but I couldn’t find reference to it anywhere

I already replied at the issues tracker but I’m planning to implement this for 4.2.