Display Last-Modified/ETag when not HTTP 304
Track the number of items seen
Only sleep if there is a delay
Handle feeds without timestamps better

Previously, feeds without <pubDate> elements had their timestamp set
to UTC now which would set the update interval to whatever the minimum
is.

With this, if a feed provided no timestamp elements of its own set the
update interval to 60 minutes.
clean_text: When cleaning text, use unicode suffix
Move open_updates/write_updates down
Just display feed URLs when adding/removing