Major Uber Progress!

- Login status and theme are saved using localStorage
- Added a Fast Build Mode to library.php, wich uses the filenames to get
file info, instead of the id3-tag
- Added "bindOnce" directive to the playlist items, this stops them from
being tracked, wich heavilly improves performance... Tho it has broken
the search function, but this will be fixed later
- Started implementing infiniteScroll, since loading over 8000 items at
once isn't that much of a great idea
- Fiddled a bit with the styles