General changes:
- Removed title item in UI

New features:
- Setting to hide UI when the video is not in browser bookmarks
- Added forwards/backwards buttons in the UI to go to previous/next consecutive video in browser bookmarks
- Setting to hide forwards/backwards buttons in the UI
- Tool in the options page to find duplicated bookmarks and unavailable YouTube videos

Bug fixes:
- Extension not loading when navigating from a non-video page to the watch video page (/watch). Extension now loads for all pages (/*).