Enable responsive Bootstrap CSS
Move container divs to the a single container div in the layout view
Change view headers; add useful contextual information
Set default content type to include charset=utf-8
Also bill new entries by default in the task_form view
Move task information link from date to comment in the time_entries view
Change default VAT rate to 21% (still overridable in the config)
Redirect back to referer after creating/updating time entries (closes: #f08f36)
Show unbilled items in timeline by default; add dropdown

This reduces the need for pagination in the timeline (refs: #a9faa0).