dovecot - Mar 2014 - + prefix in dovecot-virtual

Hi,

The "+" prefix in dovecot-virtual does not seem to be documented. 
only
discovered it because I tried to include a mailbox whose name began with 
+ and Dovecot gave me an error when I tried to copy to it.

I see it was added here:

http://hg.dovecot.org/dovecot-2.2/rev/be0f0de75e34

My dovecot-virtual file looked like this:

!+/2014-03
+/2014-02
  all

I just added another + to the second line and it seems to work.  I don't 
care about \Recent thankfully but is there a better way to specify a 
mailbox whose name begins with +?

Thanks.
-- 
Nicholas Riley <njriley at illinois.edu>