Optimize imports and continue provider standardization

sickbeard/providers/__init__.py

sickbeard/providers/alpharatio.py

sickbeard/providers/binsearch.py

sickbeard/providers/bitcannon.py

sickbeard/providers/bitsnoop.py

sickbeard/providers/bitsoup.py

sickbeard/providers/bluetigers.py

sickbeard/providers/btdigg.py

sickbeard/providers/btn.py

sickbeard/providers/cpasbien.py

sickbeard/providers/danishbits.py

sickbeard/providers/elitetorrent.py

sickbeard/providers/extratorrent.py

sickbeard/providers/fnt.py

sickbeard/providers/freshontv.py

sickbeard/providers/gftracker.py

sickbeard/providers/hd4free.py

sickbeard/providers/hdbits.py

sickbeard/providers/hdspace.py

sickbeard/providers/hdtorrents.py