[pod] Bugfix: repeated error in a for loop (https://bugs.launchpad.net/appy/+bug/394267). [gen] pod field: get the value of appy cookie 'showSubTitle' in any pod template.

pod/buffers.py

@@ -254,6 +254,10 @@ class MemoryBuffer(Buffer):
         self.elements = {}
         self.action = None
 
+    def clone(self):
+        '''Produces an empty buffer that is a clone of this one.'''
+        return MemoryBuffer(self.env, self.parent)
+
     def addSubBuffer(self, subBuffer=None):
         sb = Buffer.addSubBuffer(self, subBuffer)
         self.content += ' ' # To avoid having several subbuffers referenced at