Motivation for changes:

@mfonville reported that npo_watchlist episode entries cannot be looked up using thetvdb_lookup.

Detailed changes:

• Adding series_id_type=date to each entry, to allow episode details to be looked up using thetvdb_lookup (using broadcast date)
• Extended date parsing, to accept dates without a year specified (defaulting to current year)

Config usage if relevant (new plugin or updated schema):

            npo_watchlist:
              email: aaaa@bbb.nl
              password: xxx
              remove_accepted: yes
              max_episode_age_days: 7
            thetvdb_lookup: yes
            ...