jquery.timeselector.css: binding styles to div

++ What: ```timeselector {``` => ```div.timeselector {```
++ Why: These styles are meant exclusively for the div that houses the + / - for time selection, making the deep connection to that div explicit allows using independent / more general ```timeselector``` class(es) (defined somewhere else), esp. giving the corresponding ```input``` element the class "timeselector" without being forced to state explicitly ```input.timeselector``` (which would make no sense if you want to say very general "this input belongs somehow to a timeselector context, details open" - but not (as for div.timeselector) "this input should behave in a very, very special way")
++ Note: changing to ```div.timeselector``` is "cheaper" than changing to something like "timeselector-div" which would require to change also the JS code