tarfile.open: use os.statvfs.f_bsize as bufsize
rose bush: list: display resubmitted jobs

The old jobs of a task that has been resubmitted are not being displayed
in the list view. This change fixes that.

The time display is also improved as part of this change.
Merge pull request #987 from matthewrmshin/tarfile.open.bufsize

tarfile.open: use os.statvfs.f_bsize as bufsize
Merge pull request #988 from matthewrmshin/rose-bush.display-retry

rose bush: list: display resubmitted jobs