Use 'reference' value when creating an IMAP directory

A repositories 'reference value is always prefixed to the full folder
path, so we should do so when creating a new one. The code had existed
but was commented out since 2003, I guess the "reference" option is not
too often used.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

offlineimap/folder/IMAP.py

@@ -1,6 +1,5 @@
 # IMAP folder support
-# Copyright (C) 2002-2007 John Goerzen
-# <jgoerzen@complete.org>
+# Copyright (C) 2002-2011 John Goerzen & contributors
 #
 #    This program is free software; you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License as published by

offlineimap/repository/IMAP.py

@@ -1,6 +1,5 @@
 # IMAP repository support
-# Copyright (C) 2002 John Goerzen
-# <jgoerzen@complete.org>
+# Copyright (C) 2002-2011 John Goerzen & contributors
 #
 #    This program is free software; you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License as published by
@@ -171,7 +170,7 @@ class IMAPRepository(BaseRepository):
         return self.getconf('preauthtunnel', None)
 
     def getreference(self):
-        return self.getconf('reference', '""')
+        return self.getconf('reference', '')
 
     def getidlefolders(self):
         localeval = self.localeval
@@ -316,14 +315,9 @@ class IMAPRepository(BaseRepository):
         when you are done creating folders yourself.
 
         :param foldername: Full path of the folder to be created."""
-        #TODO: IMHO this existing commented out code is correct and
-        #should be enabled, but this would change the behavior for
-        #existing configurations who have a 'reference' set on a Mapped
-        #IMAP server....:
-        #if self.getreference() != '""':
-        #    newname = self.getreference() + self.getsep() + foldername
-        #else:
-        #    newname = foldername
+        if self.getreference():
+            foldername = self.getreference() + self.getsep() + foldername
+
         imapobj = self.imapserver.acquireconnection()
         try:
             self.ui._msg("Creating new IMAP folder '%s' on server %s" %\