Tweak Jinja2 template to substitute %2B for + in job log paths.
Merge pull request #1421 from arjclark/rose-bush.handle_non_UTC_TZ

rose bush: fix job log links for non UTC suites
Fix rose date diff returning a float.
Use is_integer on floats.
Make use of is_integer.
Merge pull request #1423 from arjclark/rose_date.ensure_int_output

Fix rose date diff returning a float.
Remove job logs database keys

Now that the job logs are nicely arranged in a directory, this sort key
functionality is no longer necessary.