Custom Title Enhanced Text Widget

I have added basic ability to use line break (br) and span tags to the widget title. Purely done by following tutorials and comments of others, as I'm not a PHP developer per se. It could certainly be improved by making things more friendly for the end user (i.e. an optional subtitle line in the admin interface, and an optional alternative styling control, so that the end user doesn't need to write any HTML). Still, this particular adaptation is something I've frequently wanted as I use subtitles a lot, and from my searches on Google, plenty of other people are looking for something similar.