Added a login throttler based on IP addresses
Significantly improved performance:
- database accesses are now mostly concurrent. Ex: makes viewers more responsive when pulling a lot of covers.
- database is optimized after each scan. Ex: "get 500 releases" subsonic command dropped from 12s to 0.2s.
Please note any existing database file is not compatible with this new version. You have to manually delete the lms.db file and restart the service.