Try best to handle user from domain not in trusted domain list.

Try best to handle user from domain not in trusted domain list.

	* cygheap.h (cygheap_domain_info::add_domain): Add prototype.
	* uinfo.cc (cygheap_domain_info::add_domain): New method.
	(pwdgrp::fetch_account_from_windows): Try to add domain explicitely
	if it was not in the original list of trusted domains and go ahead
	rather than bailing out.  Add comment to explain why.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>