Fixed handling of channel subscriptions, where new videos are added to the beginning of the playlist instead of the end.

Added 'new' field to videos, so not all the unwatched videos have 'new' badge.

app/YtManagerApp/migrations/0010_auto_20190819_1317.py

@@ -0,0 +1,23 @@
+# Generated by Django 2.2.4 on 2019-08-19 13:17
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('YtManagerApp', '0009_jobexecution_jobmessage'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='subscription',
+            name='rewrite_playlist_indices',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name='video',
+            name='new',
+            field=models.BooleanField(default=True),
+        ),
+    ]