I've dropped it accidentally with my last commit. Furthermore I moved
the data-feed-id definition to the article element and dropped multiple
references of the feed id. That's similar to what I've done before with
the data-item-id in 3dae99ac.
The article element holds the information whether a feed is disabled now.
Now it is shown if a feed had errors while updating.
The item id exists as data attribute or as element.id postfix on multiple
elements in an article.
The basic idea is to traverse the DOM tree - starting from the event firing
element - in reverse order till an article element is found.
This article element is passed to the JavaScript functions. These JavaScript
functions are getting the elements which they want to manipulate starting from
the article utilizing the JavaScript querySelector function.
The bootstrap themes had a conflicting and unused class style definied, which is
removed by now.
I had particular problems with Ctrl-N (open new window/tab)
interfering with N (go to next unread item). This change
disregards keyboard shortcuts if Alt, Shift, or Ctrl are used.
It also tries to disregard Win/Super/Meta, though this didn't
work for me in Firefox. Still, just the Ctrl is an improvement
for me.