Log Message:
Update ruby-sequel to 4.48.0.

=== 4.48.0 (2017-07-01)

* Deprecate Model.<< (jeremyevans)
* Deprecate Dataset#{and,exclude_where,range,interval}, move to
  sequel_4_dataset_methods extension (jeremyevans)
* Make Database#indexes not include partial indexes on SQLite 3.8.8+
  (jeremyevans)
* Make Database#indexes include indexes created automatically from unique
  constraints on SQLite 3.8.8+ (jeremyevans)
* Deprecate Sequel::Postgres::PG_TYPES, conversion procs should not be
  registered per-Database (jeremyevans)
* Add Database#add_conversion_proc method on PostgreSQL for registering
  conversion procs (jeremyevans)
* Deprecate unexpected values passed to Dataset#insert_conflict on SQLite
  (jeremyevans)
* Deprecate Sequel::SqlAnywhere::Dataset#convert_smallint_to_bool= method
  (jeremyevans)
* Deprecate Sequel::SqlAnywhere.convert_smallint_to_bool accessor
  (jeremyevans)
* Use savepoints around index creation if creating table inside transaction if
  ignore_index_errors is used (jeremyevans)
* Deprecate treating :natrual_inner join type on MySQL as NATURAL LEFT JOIN
  (jeremyevans)
* Deprecate Dataset#mssql_unicode_strings= on Microsoft SQL Server
  (jeremyevans)
* Preserve encoding when parsing PostgreSQL arrays (jeltz) (#1387)
* Deprecate external modification of Sequel::JDBC::TypeConvertor (jeremyevans)
* Deprecate Sequel::DB2.use_clob_as_blob accessor (jeremyevans)
* Add Database#use_clob_as_blob accessor on DB2 (jeremyevans)
* Deprecate SEQUEL_POSTGRES_USES_PG constant (jeremyevans)
* Do not swallow original exception if exception is raised inside
  Database#copy_table on PostgreSQL (jeremyevans)
* Deprecate Sequel::Postgres.client_min_messages and force_standard_strings
  accessors (jeremyevans)
* Deprecate Sequel::Postgres.use_iso_date_format accessor (jeremyevans)
* Do not allow connection in postgres adapter if postgres-pr driver is used
  and force_standard_strings is false (jeremyevans)
* Drop support for ancient postgres driver in postgres adapter, now only pg
  and postgres-pr drivers are supported (jeremyevans)
* Deprecate Sequel::MySQL.convert_invalid_date_time accessor (jeremyevans)
* Deprecate Sequel::MySQL.convert_tinyint_to_bool accessor (jeremyevans)
* Deprecate Sequel::MySQL.default_{charset,collate,engine} accessors
  (jeremyevans)
* Add Database#default_{charset,collate,engine} accessors on MySQL
  (jeremyevans)
* Make mock adapter thread safe (jeremyevans)
* Deprecate Sequel::JDBC::Dataset#convert_types accessor (jeremyevans)
* Add Dataset#with_convert_types in jdbc adapter (jeremyevans)
* Deprecate Sequel::IBMDB::Dataset#convert_smallint_to_bool= method
  (jeremyevans)
* Deprecate Sequel::IBMDB.convert_smallint_to_bool accessor (jeremyevans)
* Add Database#convert_smallint_to_bool accessor in the ibmdb adapter
  (jeremyevans)
* Deprecate sequel_3_dataset_methods extension (jeremyevans)
* Deprecate query_literals extension (jeremyevans)
* Deprecate using subtype conversion procs added after registering composite
  type in the pg_row extension (jeremyevans)
* Don't try canceling copy in Database#copy_into if copier is not created yet
  (aakashAu) (#1384)
* Deprecate global conversion procs added by pg_* extensions, when extension
  isn't loaded into Database instance (jeremyevans)
* Deprecate Sequel::Postgres::PGRange.register in the pg_range extension
  (jeremyevans)
* Deprecate Sequel::Postgres::PGArray.register in the pg_array extension
  (jeremyevans)
* Deprecate Database#copy_conversion_procs (private method) on PostgreSQL
  (jeremyevans)
* Deprecate Database#reset_conversion_procs on PostgreSQL (jeremyevans)
* Deprecate meta_def extension (jeremyevans)
* Make class_table_inheritance plugin with :alias option not use subquery for
  datasets that don't join (jeremyevans)
* Deprecate hash_aliases extension (jeremyevans)
* Deprecate filter_having extension (jeremyevans)
* Deprecate empty_array_ignore_nulls extension (jeremyevans)
* Deprecate Array#sql_array in the core_extensions extension (jeremyevans)
* Make validation_helpers plugin :allow_blank option work correctly when the
  blank extension is not loaded (jeremyevans)
* Make validation_class_methods plugin no longer require the blank extension
  (jeremyevans)
* Clear cached associations when touching associations in the touch plugin
  (jeremyevans)
* Make pg_array_associations model plugin load pg_array extension into
  database (jeremyevans)
* Remove support for :strict option in nested_attributes plugin, use
  :unmatched_pk option instead (jeremyevans)
* Make to_json class/dataset method in json_serializer plugin accept
  :instance_block option to pass block to Model#to_json (jeremyevans)
* Make to_json methods in json_serializer plugin accept blocks that are used
  to transform values before serializing to JSON (jeremyevans)
* Make Sequel.object_to_json pass block to #to_json (jeremyevans)
* Deprecate identifier_columns plugin, not needed with Sequel.split_symbols =
  false (jeremyevans)
* Make reloading column_conflicts plugin not remove existing conflict markings
  (jeremyevans)
* Deprecate cti_base_model, cti_key, and cti_model_map class methods in
  class_table_inheritance plugin (jeremyevans)
* Make Model.skip_auto_validations(:not_null) in the auto_validations plugin
  skip not null checks for columns with default values (jeremyevans)
* Make Database#copy_into in jdbc/postgresql adapter respect :server option
  (jeremyevans)
* Make #to_hash and #to_hash_groups handle options in the static_cache plugin,
  and add rename #to_hash to #as_hash (jeremyevans)
* Rename Dataset#to_hash to #as_hash, and add #to_hash as an alias, to allow
  undefing #to_hash to fix ruby calling it implicitly (jeremyevans) (#1375)
* Handle PG* constants deprecated in pg 0.21.0 in the postgres adapter
  (jeremyevans) (#1377, #1378)
* Support :association_pks_use_associated_table association option in
  association_pks plugin (jeremyevans)
* Make pg_hstore extension reset hstore conversion proc when running
  Database#reset_conversion_procs (jeremyevans)
* Fix incorrect SQL used for inserting into a CTI subclass sharing the primary
  table when using the :alias option (jeremyevans)