Use Atom namespace when getting fields, and use `<updated>` date before
`<published>`. (The dates are also available on the nsIFeedContainer
(`feedEntry`), but we're getting them directly from the fields for some
reason.)
- Hide notes, tags and related for feed items in itembox
- Add feed support for <enclosure> elements
- Add feed syncing methods for synced settings (additional work is
needed on the sync architecture to download synced settings from the
server)
- Change feed item clear policy to be less aggressive
- Adjust for deasyncification
- Disable translate-on-select
- Closeadomasven/zotero#7, Remove context menu items from feeds
