Add license info to all the files in the sickrage module

sickrage/helper/common.py

sickrage/helper/quality.py

sickrage/media/GenericMedia.py

sickrage/media/ShowBanner.py

sickrage/media/ShowFanArt.py

sickrage/media/ShowNetworkLogo.py

sickrage/media/ShowPoster.py

sickrage/show/ComingEpisodes.py

sickrage/show/History.py

sickrage/show/Show.py

sickrage/system/Restart.py

sickrage/system/Shutdown.py