Move JdbcRepositoryQuery into repository.query package. Split JdbcRepositoryQuery into AbstractJdbcQuery and StringBasedJdbcQuery.
Add QueryMapper for mapping of Criteria.
Initial support for query derivation.
Emit events and issue entity callbacks only for default RowMapper.
Custom RowMapper/ResultSetExtractor are in full control of the mapping and can issue events/callbacks themselves.
Update reference documentation.
Original pull request: #209.
