.hgignore: add vendor tree composer.json: new packages plugins/thunderbird_labels/thunderbird_labels.php: change hook and RFC822 use wrt whitelisting to avoid deprecated stuff index.php: commented debugging hooks others: new releases of vendor packages?

-- Updates from version 0.3-stable

TRUNCATE messages;
CREATE INDEX messages_index_idx ON messages (user_id, cache_key, idx);
DROP INDEX contacts_user_id_idx;
CREATE INDEX contacts_user_id_idx ON contacts (user_id, email);