Log Message:
Update ruby-sequel to 3.44.0.

=== 3.44.0 (2013-02-04)

* Speedup mysql2 adapter with identifier output method fetch speed by up to
  50% (jeremyevans)

* Speedup tinytds adapter fetch speed by up to 60% (jeremyevans)

* Expand columns_introspection extension to consider cached schema values in
  the database (jeremyevans)

* Expand columns_introspection extension to handle subselects (jeremyevans)

* Have #last and #paged_each for model datasets order by the model's primary
  key by default (jeremyevans)

* Improve emulated offset support to handle subqueries (jeremyevans)

* Remove use of Object#extend from the eager_each plugin (jeremyevans)

* Add support for temporary views on SQLite and PostgreSQL via the :temp
  option to create_view (chanks, jeremyevans)

* Emulate Database#create_or_replace_view if not supported directly
  (jeremyevans)

* Add Dataset#paged_each, for processing entire datasets without keeping all
  rows in memory (jeremyevans)

* Add Sequel::ConstraintViolation exception class and subclasses for easier
  exception handling (jeremyevans)

* Fix use of identity_map plugin with many_to_many associations with right
  composite keys (chanks) (#603)

* Increase virtual row performance by using a shared VirtualRow instance
  (jeremyevans)

* Allow the :dataset association option to accept the association reflection
  as an argument (jeremyevans)

* Improve association method performance by caching intermediate dataset
  (jeremyevans)