Provide DocHistory entries with a docalias_set property (that of the associated document).

 - Legacy-Id: 9473

Author: levkowetz

ietf/doc/models.py

@@ -562,6 +562,10 @@ def last_presented(self):
     def groupmilestone_set(self):
         return self.doc.groupmilestone_set
 
+    @property
+    def docalias_set(self):
+        return self.doc.docalias_set
+
     class Meta:
         verbose_name = "document history"
         verbose_name_plural = "document histories"