Add generator wrapper to fetch RedFams by status and ending

Related Task: [https://fs.golderweb.de/index.php?do=details&task_id=26 FS#26]

lib/redfam.py

@@ -467,6 +467,19 @@ class RedFamWorker( RedFam ):
                 print(fam)
                 raise
 
+    @classmethod
+    def gen_by_status_and_ending( cls, status, ending ):
+        """
+        Yield red_fams stored in db by given status which have an ending after
+        given one
+        """
+        mysql = MysqlRedFam()
+        for fam in mysql.get_by_status_and_ending( status, ending ):
+            try:
+                yield cls( fam )
+            except RedFamHashError:
+                print(fam)
+                raise
 
 class RedFamError( Exception ):
     """