Features:
- Video support!
- Filtering/sorting
- Snoozing
- New review screen dialog
- Separate preferences into different categories
- Add preference to start statistics week on Monday
- Add preference to disable statistics
- Configurable period to remember swipes for
- Added a tutorial for new users
- Open photo/video in external gallery app

Fixes:
- Require 2 system back gesture/button presses to exit app
- Week title in statistics page now shows the correct dates