* message-list.c (ml_set_value_at): Implement clicking on the
envelope icon to set read/unread. Based on a patch by clahey.
(select_msg): keep the timeout id for the "seen" flagging in the
message_list structure, so ml_set_value_at can clear it so it
doesn't re-mark a message seen after you click it unseen.
svn path=/trunk/; revision=3601