rss-feed 2.0-beta

• Replaced incoming data handling and menu update procedures (large performance boost)
• Various bugfixes and increased fault tolerance
• Replaced RSS source 'paging' system with a scrollable menu (maximum menu height may be set)
• Added new article notification system
• Mark unread articles in menu, show unread count in status area
• Complete rework of the settings widget, added source verification
  • Keep the plugin active when Gnome session locks / blanks screen (by default, all plugins are disabled at this point)
  • Poll delay - minimizes performance impact on gnome-shell by rate-limiting source queries
  • Toggle debug mode
  • Reload plugin button (depends on 'gnome-shell-extension-tool')
  • Panel menu:
    • Maximum number of shown articles per source
    • Toggle menu animations
    • Set menu button alignment (top/bottom)
    • Toggle update detection
    • Show article descriptions when selected
  • Notifications:
    • Toggle on/off
    • Set notification limit
    • Remove when plugin disabled
    • Toggle show on lock screen
  • RSS sources:
    • Added 'Status' colum, displays source validation result
    • Recheck all sources button, double click on a source to recheck it
    • Removed 'Edit' button, made URL column cell editable (click selected row to edit)
    • Made list reorderable (drag to reorder)
    • Added buttons to move selected item up/down
  • Note that certain features require plugin restart to take effect
• Added plugin restart button (shown only in debug mode) - this reinitializes the plugin so gnome-shell does not have to be restarted after editing the source
• Fixed REXML HTML attribute parsing bug