nzbget / cleanup

* Remove unused socks tvdb proxy modification left overs.
* Add ability to set nzbget username.
* Add real priority for nzbget 9.0+ instead of just adding to the top of the queue (Prinz23).
* Add exception handling when connecting to nzbget (Prinz23).
* SB-API cleanup
* APIBuilder - limit showlist to 100 items for performance reasons
* Lower default RSS search freq. from 60min to 40mins.