Photo roll UI improvments
Created by: dark-eye
Improved the Photo roll UI a little :
- Implemented Camera App #35 (closed) Adjustable thumbnails in photo roll.
- Improved the grid to single photo transition
- Added bottom edge action to go back from single photo to photo roll
- Blurred the background of the header
- Removed the gallery app link in single photo to avoid confusion.
Also changed the maintainer to point to Ubports.