only change background on net going up if we won’t also reload the RSS feed
- added ability to mark images as favorite
- clear out the oldest items when we hit a high water mark (100), but don’t delete ones tagged as favorite
- when a url fails to load then pull it from the image dict
- set the check mark state in the favorite menu item if this image is a favorite
- change markasfavorite to toggle the favorite state
- added ability to jump back to the previous background
- when changing background show the least viewed ones first, then within that set the oldest
- keep track of view count properly
- update favorite menu item check state when changing favorite status while on an image too
- fix previous background command to update the newly loaded entry in the status menu and load time
- added ability to delete an image from the view list and never show again