Allow Blender to mark shots as used/not used in edit.

NOTE: requires schema change, so be careful.

tests/test_shots.py

@@ -339,6 +339,38 @@ class PatchShotTest(AbstractShotTest):
         }
         self.patch(url, json=patch, auth_token='other', expected_status=403)
 
+    @responses.activate
+    def test_patch_unlink(self):
+        shot = self.create_shot()
+        self.create_valid_auth_token(ctd.EXAMPLE_PROJECT_OWNER_ID, 'token')
+
+        url = '/api/nodes/%s' % shot._id
+
+        dbnode = self.get(url, auth_token='token').json()
+        self.assertNotIn('used_in_edit', dbnode['properties'])
+
+        patch = {'op': 'unlink'}
+        self.patch(url, json=patch, auth_token='token')
+
+        dbnode = self.get(url, auth_token='token').json()
+        self.assertFalse(dbnode['properties']['used_in_edit'])
+
+    @responses.activate
+    def test_patch_relink(self):
+        shot = self.create_shot()
+        self.create_valid_auth_token(ctd.EXAMPLE_PROJECT_OWNER_ID, 'token')
+
+        url = '/api/nodes/%s' % shot._id
+
+        dbnode = self.get(url, auth_token='token').json()
+        self.assertNotIn('used_in_edit', dbnode['properties'])
+
+        patch = {'op': 'relink'}
+        self.patch(url, json=patch, auth_token='token')
+
+        dbnode = self.get(url, auth_token='token').json()
+        self.assertTrue(dbnode['properties']['used_in_edit'])
+
 
 class RequiredAfterCreationTest(AbstractShotTest):
     """