dict_value and list_value truncated at 64kiB on MySQL

[Qalthos]

Under the hood of SQLAlchemy, PickleType is just LargeBlob, which under MySQL is mapped to BLOB. BLOB (in MYSQL) has a max size of 64kiB, rather than MEDIUM_BLOB or LONG_BLOB, which store larger amounts. In other words, it works, just not for very long.