Changes the internal ratelimiting scheme.

Rather than ratelimit to one request per-second, attempt to detect the
MusicBrainz API ratelimiting. The API will return HTTP 503 errors once
ratelimiting has begun. Once this has been detected, the script will wait 1
second before continuing processing.

get_artist_art.py

@@ -39,4 +39,4 @@ for artist in dir_list:
             print(e)
         
         count += 1
-        sleep(1)
+        #sleep(1)