Create unique GUID URL's for NZBDrone compatibility

As per http://forums.nzbdrone.com/t/2097 the Develop branch now identifies release by GUID. 

I barely know anything about python so this took some time to do but seems to work well. NZB MegasearcH by default just used a bogus URL for GUID, I've replaced it with a random UUID which should always be unique.

Results before change (Note line #9): https://pastebin.com/jGfdca9i

After: https://pastebin.com/G5q1jx48