- More general tasks
        - Know about @book
        - Maybe uncrossref in tmp.bib
        - Maybe pull important papers to the start of their sections?
        . Clean \{}~ when going from note to url; add \{}~ when making
          note from url.
        . Also clean \_ to _ and back
        - Look for urls in wherepublished.
        . Forgive newlines in wherepublished, note.
        - When sorting by date, entries with unknown months go into a magic
          "month zero" before January.  Is this right?

- Cache tasks
	- Generate a list of broken links
	- Re-download all cached items if requested
	- Clear dead items from cache
	- Use HTTP HEAD requests to decide whetherto update stale
          elements in cache.
	- Add ability to honor a "www_no_cache={1}" option for entries
          if the authors ask us not to cache them.
	- Maybe, add ability to cache images from an HTML page.