Need to issue these separately, since they may all independently throw an exception

Unsubscribe already taken care of in deleteMailbox()
[mms] Some IMAP servers require a mailbox to be unselected before it can be renamed.
Actually append the 3rd example message to the server
Update package.xml for 2.5.0 release
Released Horde_Imap_Client-2.5.0
Development mode for Horde_Imap_Client-2.5.1