Apply nametrans to all Foldertypes

getvisiblename() was only defined on IMAP(derived) foldertypes, but we
want it on eg. Maildirs too, so we define it centrally in Folder.Base.py
rather than only in folder.IMAP.py.

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

offlineimap/folder/IMAP.py

@@ -40,7 +40,6 @@ class IMAPFolder(BaseFolder):
         self.sep = imapserver.delim
         self.imapserver = imapserver
         self.messagelist = None
-        self.visiblename = repository.nametrans(name)
         self.randomgenerator = random.Random()
         #self.ui is set in BaseFolder
 
@@ -67,9 +66,6 @@ class IMAPFolder(BaseFolder):
     def getcopyinstancelimit(self):
         return 'MSGCOPY_' + self.repository.getname()
 
-    def getvisiblename(self):
-        return self.visiblename
-
     def getuidvalidity(self):
         imapobj = self.imapserver.acquireconnection()
         try: