innerText is not W3C-compliant and undefined in Firefox
reload all pages with a page counter if feed is empty

An explicit reload was missing on the feed-items page. This should
cover now all pages.
keep special page title "(counter) feedtitle" on the feed items view
sync javascript variable names with php

variable source is used in controllers/bookmark.php and templates/show_item.php
reload page if no article is left in view

Do it that way to till automatic fetching of more articles via Ajax
($pagecounter > $articles) is implemented.
Merge branch 'bugfixes'
display the number of unread items on every page with an "unread items" menu
do not add zero counter to title
always update the unread items counter

Update the unread items counter when an item is removed or marked
as read/unread.