In some cases, a feed will not yet exist in RSS_TICKER_FEED_MANAGER.feeds when an item from the feed is marked as read, such as immediately after a restart.

This may just be a hiccup during development. This change might be reverted later.
Inline options panel.
Localized toolbaritem.
Adding the subscribe button on firstrun.
Confirming multiple tab creation before opening all in tabs.
The entire item data object is stored, not an array of properties.