Responsive library

Switching to tabs view when screen get too small
+ remove duplicates
Merge pull request #40 from jotak/master

Responsive library
Merge pull request #41 from ning-yu/master

Beginning Spotify Integration
Reworking Settings Page
Update _header.php
Bugs fixes: spinner spins + AlbumArtist
Merge pull request #42 from jotak/master

Bugs fixes: spinner spins + AlbumArtist