Don't let the parser crash if it could not update the feed

If a feed is returning that the feed is not available temporarily (and
does this using HTML), don't crash but just log errors for now.
Whitespace cleanup
Fix regression that adding categories to the root did not work
Workaround that click events on a link in the content caused a scroll

This is not a clean solution, but works around the most common case. This needs
to be revisited.
Make toast() invokable multiple times
Fix scrolling logic to work a little bit more robust
New DAO methods to return the amount of starred entries
Workaround off-by-one problems due to high replication storage

When you update an entry (e.g. mark it read) and immediately query the number of read
entries, it will sometimes return the wrong number. Let's calculate the number by
hand for now until we figure out, why this happens (e.g. due to our entitymanager in
view pattern).
Implement display of starred entries
Drop unused graphic