Table schema:
CREATE TABLE table_name_79 (wysiwyg_editor VARCHAR, image_attachment VARCHAR, user_selectable_themes VARCHAR, unread_message_tracking VARCHAR)

Question: Which WYSIWYG Editor has a User-selectable themes of yes, and an Unread message tracking of session, and an Image attachment of plugin?
SQL: SELECT wysiwyg_editor FROM table_name_79 WHERE user_selectable_themes = "yes" AND unread_message_tracking = "session" AND image_attachment = "plugin"