Formalizes the existential comics process

__main__.py

@@ -9,6 +9,7 @@ from urllib.parse import urlparse
 from pathlib import Path
 from comic_download import Comic, find_comic_class
 import comic_download.xkcd
+import comic_download.existential_comics
 
 def setup_args():
     parser = argparse.ArgumentParser(
@@ -81,9 +82,9 @@ if __name__ == "__main__":
             r = [comic.get_latest_strip()]
         else:
             r = comic.get_all_strips()
-            start = args.start or 0
-            end = args.end or (len(r) - 1)
-            r = r[start:end + 1]
+            start = args.start or comic.get_first_strip()
+            end = args.end or comic.get_latest_strip()
+            r = r[start - 1:end]
     
         for index in reversed(r):
             t = threading.Thread(name=str(comic) + str(index), target=load_strip, args=(base_path, comic, index, args.plain, thread_limit))