Added expireScreenshots option

- Added expireScreenshots option
- Copied from UniverseSyncCache because I was too lazy to think of a
better way to do it.
- Screenshots older than a day will be deleted.
Forgot .csproj
Updated so now it deletes screenshots each second.
Some changes

- Changed time to clean screenshots from 1 second to 30 minutes
- Fixed bugs
Fixed some bugs.
Fixed merge conflict