Fixed types of owner_id and original_owner_id in table die from TINYINT to SMALLINT

Fixes #534. I think that the clearing of the database in #534 shouldn't be necessary any more, thus the fixes tag.

This would have caused problems on the production site as soon as we had more than 255 users.

Requires database update: 00534_unit_test_crash_01.sql.

http://jenkins.buttonweavers.com:8080/job/buttonmen-blackshadowshade/160