Bug 6796: Take CalenderFirstDayOfWeek and TimeFormat into account

Bug 6796: Take CalenderFirstDayOfWeek and TimeFormat into account

This patch adds accounting for the `CalendarFirstDayOfWeek` and
`TimeFormat` preferences in the libraries management pages.

We respect CalendarFirstDayOfWeek for both input and display, but we
only respect TimeFormat for input at this time. We need a new template
helper and js helper for formatting just time in the appropriate format,
currently we only have such formatters for full datetimes.

Sponsored-by: PTFS Europe
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>