* camel-service.c (service_disconnect): Add a new argument, clean,
	that says whether or not to try to disconnect cleanly.

	* camel-remote-store.c (remote_send_string, remote_send_stream,
	remote_recv_line): disconnect uncleanly on failure to prevent
	infinite loops when providers would normally send commands from
	disconnect(). Remove some unneeded CamelException goo.

	* providers/smtp/camel-smtp-transport.c (smtp_disconnect):
	* providers/pop3/camel-pop3-store.c (pop3_disconnect):
	* providers/nntp/camel-nntp-store.c (nntp_store_disconnect):
	* providers/imap/camel-imap-store.c (imap_disconnect): Don't send
	QUIT/LOGOUT if !clean.

svn path=/trunk/; revision=6303