[imp] rename imap subfolder - bug

[Makeri Kutsonu]

Hello !

We have a IMAP-Server, where the Folder are : .Folder.Subfolder ...

If i rename a Subfolder. then preallocated only "Subfolder".

If i rename it to e.g. "Subfolder-renamed", then this Folder is not a Subfolder,
it is on top-level : .Subfolder-renamed

I found it is better, if preallocated the full-Foldername (Folder.Subfolder) -
else the User thinks, the Folder is deleted - its confusing.