Updated feeds

- Map node ids to resources
- Map Scheduler publish/unpublish times to display start/end
- Include unpublished nodes with a scheduled publication time to allow precise publication in app
- Sort feed items by node update time
- Increase maximum number of feed items to 100
- Move app part of app feed url to end to indicate that it is a variation of the original feed
Add rules based caching of feeds.

- Feed caches are updated on content updates og flagging for the corresponding node types
- Updated display ids for clarity
Fix strict warning: Only variables can be passed by reference.