Re-structured public/ and moved the coffeescripts

Moved stylesheets into public/css, added a vendor folder for the reset,
fonts and font-awsesome. Did the same with js files, but into public/js.

Moved coffeescripts into coffee/ and added a core/ folder inside to
seperate per-page scripts from global ones. Also set the server to
listen for *.js files in /coffee, instead of .coffee (prevents mimetype
issues).

General updates throughout to reflect the new directories
Cleaned up CSS and HTML, fixed sidebar click bug

Swapped out the #header for a normal <header> tag, added a proper
footer, and made some other minor changes. Merged a few CSS styles as a
result.

Fixed the sidebar bug, where pjax was not stopping the event from
bubbling.
Added handling for the top next/prev buttons
Commented out excess fonts, fixed seek bar positioning
Updated pjax
Added proper spacing for player screen
Swapped out string concat with interpolation for player label spacing
Merge branch 'master' of https://github.com/Mirceam94/boombox into Mirceam94-master