display the number of unread items on every page with an "unread items" menu
always update the unread items counter

Update the unread items counter when an item is removed or marked
as read/unread.
Merge branch 'counter' into counter_css
add brackets to unread counter via CSS

This makes processing of counters in javascript way more easier. Confirmed
working with IE9, Firefox 24.6, Chrome 36, Mobile Safari on iOS6.

This should be extended to pagecounters as well. Right now it isn't possible, as
these counters aren't unified (special case on unread page).

It isn't a problem at all, as long as pages with empty counters have a redirect.
Otherwise an ugly "(0)" is displayed.
add brackets to page and feed items counter via CSS

Unified pagecounters