Added Spotify Web Player

I needed a Spotify Web Player Parser since my other extension broke with the 64 bit version of Chrome.
I saw from Sourceforge that it would have supported it, but it didn't.
So i made this little fix where i can continue to stream my music... more or less.
I'm new to coding but i did this little addition to this older version.
I would like to see the plugin updated with this addition (And if you can, improve the code, this was my best)
*Doesn't require Groovemarklet*