1. 'auth_method' in config, where users can select between
'password' and 'token'.
2. create index for token, avoid iterating the entire user
section when validating tokens.
3. only generate token for a user when there's no token for
him in the db, avoid tokens fill the db.
* Implement button toolbar
* Fix filters logic
* Switch to btn-primary for active filters
* Reduce playlist table columns on mobile
* Cleanup playlist area
* Reduce volume spacing
* Hide items in playlist as well for mobile
* Use text utility classes vs style
* Filter use checkbox instead of radio
* Hide library file column on mobile
* Update jQuery and FontAwesome to latest
