Singleshot 2.0.0a3

I slowly creep towards a ‘final’ 2.0.0 release. It’s mostly bug fixes now based on reports from my legions of dedicated testers. In a3, the caching problem when in persistent mode is fixed. Also an issue with Apache 2 and I added pagination of the album pages to sidestep a problem when Singleshot is pointed at a huge directory of images (1000+).