Adds favicon
Temporarily fixes volume jump issue.

Need to figure out the cause still
* playlists data rendered on '.selector' was having an extra playlist with 'id:undefined'
* adds space between text on login-message
Ensures pause icon is shown when song is playing

When in paused state, if user clicked on next, icon was not being changed before
Adds piwik tracking
Adds code for seek. Currently doesn't work due to bug in howler.js
Updates howler.js to v1.1.19 and changes code for seek
Adds seek specific styles
Fixes issue with duration indicator jumping on seek