Bug 37888: Show all jobs, order by "queued", remove last hour filter

Bug 37888: Show all jobs, order by "queued", remove last hour filter

By default the background jobs page now shows the most recently queued
jobs, whatever their status is.

By doing that, the jobs enqueued less an hour ago are always visible if
there are any (well, the first page at least), so the "last hour" filter
becomes way less useful and it's better to remove it as it caused
problems (see bug 37905) and the "1 hour" duration was arbitrary.

The "current jobs only" filter is still useful as lots of quick
background jobs can push running jobs away from the first page and it's
a common use case to list running jobs

Test plan:
1. Start some background jobs (batch item modification for instance)
2. Make them run and wait for finish
3. Stop the background jobs workers
4. Start some more background jobs
5. You should now have running and non-running background jobs. Go to
   the admin background jobs page
6. Verify that all background jobs are shown and that they ordered by
   queued time (last queued job first)
7. Verify that "Current jobs only" filter still works

Signed-off-by: Eric Phetteplace <phette23@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>