Search Implementation & SkipCache

- New SearchActivity for search results
- Search term shows up as ActionBar subtitle
- Separate search menu
- Moved action options menu to FeedFragment
- Set RSSManager cache max size to 30 minutes
- New API for overriding Cache (useful for force refreshing)
- Useful http request logging
- Removed Request getter methods and just use public variables instead
- Slightly refactored FeedFragment
- FeedFragment refresh now works
- Action Bar progress shows upon first load
- FeedFragment now uses a default feed if none was passed