Allow to pass 'force' arg to selectro() to enforce a new select

Pass through the 'force' argument from selectro() to select() so that it
can also enforce a new SELECT even if we already are on that folder.

Also change the default parameter from '0' to 'False' to make clear that
this is a Bool.

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

offlineimap/imaplibutil.py

@@ -40,7 +40,7 @@ class UsefulIMAPMixIn(object):
             return self.mailbox
         return None
 
-    def select(self, mailbox='INBOX', readonly=False, force = 0):
+    def select(self, mailbox='INBOX', readonly=False, force = False):
         """Selects a mailbox on the IMAP server
 
         :returns: 'OK' on success, nothing if the folder was already