Added Logitech Media Server support.

Saw another chap a while ago wanted this feature in headphones, and considering I too use Squeezebox for my music playing system, I figured I may as well slap this together.

Really basic but functional system atm that basically just sends a JSON 'rescan' request to the host defined in the settings window upon completion of post processing.

Please bare in mind that I'm VERY new to Python, so this may be riddled with inefficiencies. It works on my system, no bugs so far, but considering my lack of Python knowledge, there were probably a million better ways of doing this.

Hope you can get some use out of this.