= New Features

* An association_multi_add_remove plugin has been added.  This plugin
  adds a shortcut for adding or removing multiple associated objects
  in a single method call:

    Artist.plugin :association_multi_add_remove
    Artist.many_to_one :albums
    Artist[1].add_albums([Album[2], Album[3]])
    Artist[1].remove_albums([Album[4], Album[5]])

  It also offers a setter method, which will add and remove associated
  objects as necessary:

    Artist[1].albums = [Album[3], Album[4]]

= Other Improvements

* The sharding plugin now integrates with the server_block extension.
  This makes it so if you retrieve a model instance inside a
  with_server block, saving the model instance will save it back to
  the shard from which it was retrieved.

* Setting a default for a column on Microsoft SQL Server now works
  correctly if the column already has a default.

* Sequel::SQL::NumericMethods#coerce no longer raises NoMethodError
  if the super method is not defined.  This fixes some cases when
  comparing Date/DateTime instances to Sequel objects.

* The csv_serializer plugin now avoids keyword argument separation
  issues on Ruby 2.7+.