Settings page draft.

Implements a basic feed list and the dialog box which will allow to add a new feed and edit an existing one.
Right now these dialogs just display the feed informations.
The very same html elements are used for both dialogs, initializing the fields using appropriate values for the.
Add new "getFeedByID" method to Options object
Reflect the order of feeds in settings permanent.

In the settings page you can now reorder the feed in the list by drag&drop operation
and the new order will be shown in the popup window.
To achieve this the options.Feeds array is changed and stored in the cloud at each
drag&drop operation. While this is a bit costly, it ensures that the preferences will always
be up to date (given the internet connection works).
Apply the reordering-store feature to all ".list" elements
Add/edit/delete feed buttons in settings now work.

Small bugfix in getFeedByID method.
Ctrl-click in popup mark the item as read without opening it.
Minor refactoring
Add local caching of feed results and badge notification of unread feeds.