Multi Library Support and Plex TMDB ID lookups

Updated code and a slightly different format in the settings file now allows support for multiple library parsing. This update will create metadata, keys, and overlay files for each library specified in settings. This is a rather complicated update, as it also supports local TMDB ID lookups before attempting to search, so at minimum vars.py needs deleted and settings.yml needs updated as follows:

library_name:

• Your Library
  days_ahead: 30 # This allows customization of the look ahead days (to be considered "Returning Soon") up to 90 days.