update README
add dlsub.py which meant to replace functionality of download_subtitle.py by using subliminal api rather than using command line interface to download subtitles. by using so there is no need to keep track of which files goes into exception list or which files downloaded these tasks are automated right now.
start implementing dlsub.py rather than download_subtitle.py in main.py
Merge branch 'master' of https://github.com/darthvish/subtitle_automate