Fixed twitter share link, added facebook share, direct back to '/' when ammo title clicked, turn cursor into pointer when hovering over songs. Remove song functionality

https://github.com/ammoio/ammo/issues/90
https://github.com/ammoio/ammo/issues/108
https://github.com/ammoio/ammo/issues/109
https://github.com/ammoio/ammo/issues/114