refactor models, change map package storage and map package loading

src/c3nav/mapdata/management/commands/loadmap.py

@@ -1,19 +1,19 @@
 from django.core.management.base import BaseCommand, CommandError
 from django.db import transaction
-from ...packageio import MapPackagesIO
+
+from ...packageio import read_packages
 
 
 class Command(BaseCommand):
-    help = 'Load the given map packages into the database'
+    help = 'Update the map database'
 
     def add_arguments(self, parser):
-        parser.add_argument('mappkgdir', nargs='+', type=str, help='map package directories')
         parser.add_argument('-y', action='store_const', const=True, default=False,
                             help='don\'t ask for confirmation')
 
     def handle(self, *args, **options):
         with transaction.atomic():
-            MapPackagesIO(options['mappkgdir']).update_to_db()
+            read_packages()
             print()
             if input('Confirm (y/N): ') != 'y':
                 raise CommandError('Aborted.')