= New Features

* You can now change the level at which Sequel logs SQL statements,
  by calling Database#sql_log_level= with the method name symbol.
  The default is still :info for backwards compatibility. Previously,
  you had to use a proxy logger to get similar capability.

* You can now specify graph aliases where the alias would be the same
  as the table column name using just the table name symbol, instead
  having to repeat the alias as the second element of an array.  More
  clearly:

    # < 3.17.0:
    DB[:a].graph(:b, :a_id=>:id).
      set_graph_aliases(:c=>[:a, :c], :d=>[:b, :d])
    # >= 3.17.0:
    DB[:a].graph(:b, :a_id=>:id).set_graph_aliases(:c=>:a, :d=>:b)
    
  Both of these now yield the SQL:
  
    SELECT a.c, b.d FROM a LEFT OUTER JOIN b ON (b.a_id = a.id)

* You should now be able to connect to MySQL over SSL in the native
  MySQL adapter using the :sslca, :sslkey, and related options.

* Database#views and Database#view_exists? methods were added to the
  Oracle adapter, allowing you to get a an array of view name symbols
  and to check whether a given view exists.

= Other Improvements

* The nested_attributes plugin now avoids unnecessary update calls
  when deleting associated objects, resulting in better performance.

* The optimistic_locking plugin now increments the lock column if no
  other columns were modified but the Model#modified! was called. This
  means it now works correctly with the nested_attributes plugin when
  no changes to the main model object are made.

* The xml_serializer plugin can now round-trip nil values correctly.
  Previously, nil values would be converted into empty strings.  This
  is accomplished by including a nil attribute in the xml tag.
  
* Database#each_server now works correctly when using the jdbc and do
  adapters and a connection string without a separate :adapter option.
  
* You can now clone many_through_many associations.

* The default wait_timeout used by the mysql and mysql2 adapters was
  decreased slightly so that it works correctly with MySQL database
  servers that run on Windows.
  
* Many improvements were made to the AS400 jdbc subadapter.

* Many improvements were made to the swift adapter and subadapters.

* Dataset#ungraphed now removes any cached graph aliases set with
  set_graph_aliases or add_graph_aliases.
