Minor changes to pull before new build.

Tweak RawHD regex to accept mpeg2 and mpeg-2 in the filename.
Add missing ek.ek wrap around isdir check that was reported on the forums:
  http://sickbeard.com/forums/viewtopic.php?f=4&t=6829#p32324
PEP8 whitespace cleanup for postProcessor.py while I was at it.