Migrate to use a local model for document comments. Closes gh-issue #233.

mayan/apps/document_comments/models.py

@@ -0,0 +1,29 @@
+from __future__ import unicode_literals
+
+from django.conf import settings
+from django.db import models
+from django.utils.translation import ugettext_lazy as _
+
+from documents.models import Document
+
+
+class Comment(models.Model):
+    document = models.ForeignKey(
+        Document, db_index=True, related_name='comments',
+        verbose_name=_('Document')
+    )
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL, editable=False, related_name='comments',
+        verbose_name=_('User'),
+    )
+    comment = models.TextField(verbose_name=_('comment'))
+    submit_date = models.DateTimeField(
+        auto_now_add=True, db_index=True,
+        verbose_name=_('Date time submitted')
+    )
+
+    class Meta:
+        get_latest_by = 'submit_date'
+        ordering = ('-submit_date',)
+        verbose_name = _('Comment')
+        verbose_name_plural = _('Comments')