Fix minor style issues in StockSource/StockWidget

This pull request fixes some minor style issues in StockSource and StockWidget. Most are whitespace-issues, but some unused code is also removed.
I also agree on having a default title when the widget is intended to be show one (`ClockWidget` don't have one, for instance).

What do you mean with "very specific source"? `BuildWidget` has a title suitable for any build status list (which is the point of the widget itself, but it isn't tied to the Jenkins source). I believe `ScrumWidget` doesn't have a default simply because we forgot to add one (something like "Tasks" or "Sprint" would work). Anyway, as anyone can override the title in the config, I don't think the choice of the title it is that important. ;)