:class:`~imaplib.IMAP4` and :class:`~imaplib.IMAP4_SSL` now have an 
optional *timeout* parameter for their constructors. 
Also, the :meth:`~imaplib.IMAP4.open` method now has an optional *timeout* parameter
with this change. The overridden methods of :class:`~imaplib.IMAP4_SSL` and
:class:`~imaplib.IMAP4_stream` were applied to this change. Patch by Dong-hee Na.
