= New Features

* SQL::GenericExpression#=~ has been added as an alternative method
  of specifying equality/inclusion/identity.  Previously, you had to
  use a hash.  This led to some slightly weird looking syntax when
  used inside virtual rows:

    DB[:items].where{{function(:column)=>0}}
    # SELECT FROM items WHERE function(column) = 0

  You can now use =~ as an equivalent:

    DB[:items].where{function(:column) =~ 0}
    # SELECT FROM items WHERE function(column) = 0

  Like when using a hash, this works also for inclusion:

    DB[:items].where{function(:column) =~ [1,2,3]}
    # SELECT FROM items WHERE function(column) IN (1, 2, 3)

  for identity:

    DB[:items].where{function(:column) =~ nil}
    # SELECT FROM items WHERE function(column) IS NULL

  and for matching (on MySQL/PostgreSQL):

    DB[:items].where{function(:column) =~ /foo/i}
    # SELECT FROM items WHERE function(column) ~* 'foo'

  This new syntax makes more complex conditions simpler to express:

    DB[:items].where{(function(:column) =~ 0) | (column =~ 1)}
    # SELECT FROM items WHERE function(column) = 0 OR column = 1

  compared to previous versions of Sequel:

    DB[:items].where{Sequel.|({function(:column) => 0}, {:column => 1})}

  On ruby 1.9+, you can also use SQL::GenericExpression#!~ to invert
  the condition:
    
    DB[:items].where{function(:column) !~ 0}
    # SELECT FROM items WHERE function(column) != 0

    DB[:items].where{function(:column) !~ [1,2,3]}
    # SELECT FROM items WHERE function(column) NOT IN (1, 2, 3)

    DB[:items].where{function(:column) !~ nil}
    # SELECT FROM items WHERE function(column) IS NOT NULL

    DB[:items].where{function(:column) !~ /foo/i}
    # SELECT FROM items WHERE function(column) !~* 'foo'

  This makes it simpler to write inverted conditions.  Ruby 1.8
  doesn't support overriding the !~ method, but you can still use the
  unary ~ method to invert:

    DB[:items].where{~(function(:column) =~ 0)}

* Database#add_named_conversion_proc has been added on PostgreSQL to
  make it easier to add conversion procs by name instead of by OID:

    DB.add_named_conversion_proc(:citext){|s| s}

* Database#full_text_search on PostgreSQL now supports :tsquery and
  :tsvector options for using existing tsquery and/or tsvector
  arguments, instead of assuming the arguments are query terms or
  the text to be search.

= Other Improvements

* Database#transaction now works inside after_commit and
  after_rollback hooks.  Previously, it didn't work correctly as it
  thought it was already inside the previously committed/rolled back
  transaction.

* Sequel.pg_jsonb now returns JSONBOp instances instead of JSONOp
  instances when passed other than Array or Hash.

* The tinytds adapter no longer tries to cancel a query on a closed
  connection, which was causing an exception to be raised.

= Backwards Compatibility

* The default root name used in the JSON serializer is now demodulized
  before being underscored.  This changes the behavior when the model
  is namespaced.  For example, if the model class name is Mod::Model,
  the previous default root name would be "mod/model", the new default
  root name is "model".

* If you were calling =~ or !~ on SQL::GenericExpression objects and
  expecting the default ruby behavior of returning nil for =~ and
  true for !~, you'll have to update your code.