= New Features

* An :auto_increment key has been added to the schema information for
  primary key columns on JDBC, PostgreSQL, MySQL, MSSQL, DB2, and
  SQLite.  This fixes issues in the schema_dumper extension where
  non-auto-incrementing integer primary keys are no longer dumped as
  auto-incrementing.

  For adapters that don't have specific support for detecting
  auto incrementing primary keys, Sequel now assumes a primary key
  is auto incrementing only if it is not a composite primary key
  and the type contains int (e.g. int, integer, bigint).

= Other Improvements

* Dataset#empty? now ignores any order on the dataset.  Previously,
  calling empty? on a dataset ordered by an alias in the SELECT list
  could raise an exception.

* Schema qualified tables are now handled correctly in
  many_through_many associations.

* Using a hash as the value for the :eager association option now
  works correctly.

* All PG::ConnectionBad exceptions are now treated as disconnect
  errors in the postgres adapter.  This should be more robust than
  the previous method of trying to recognize disconnect errors by
  trying to parse the exception message.

* Sequel now skips a hash allocation when issuing queries through
  datasets if sharding is not used.

* Sequel no longer uses the JDBC schema parsing in the jdbc/sqlserver
  adapter.  Instead, it uses the MSSQL schema parsing, which should
  be more accurate than the generic JDBC schema parsing.
