better mimetypes

Also needs:

```sql
ALTER TABLE paste DROP raw;

DELIMITER @@

DROP PROCEDURE IF EXISTS insert_paste@@
CREATE PROCEDURE insert_paste (
  p_uuid BINARY(16),
  p_content MEDIUMBLOB,
  OUT p_id MEDIUMINT
)
BEGIN
  START TRANSACTION;
  INSERT paste (uuid, digest, content)
  VALUES (p_uuid, UNHEX(SHA1(p_content)), p_content);
  SELECT last_insert_id() INTO p_id;
  COMMIT;
END;
@@

DROP PROCEDURE IF EXISTS get_content@@
CREATE PROCEDURE get_content (
  p_id MEDIUMINT,
  OUT p_content MEDIUMBLOB
)
BEGIN
  SELECT content INTO p_content
  FROM paste
  WHERE id = p_id;
END;
@@
```