--- Class.new([superclass])
--- Class.new([superclass]) {|klass| ... }

    ̾դƤʤ superclass Υ֥饹ޤ
    superclass ά줿ˤObject Υ֥饹
    ޤ

    ̾Τʤ饹ϡǽ̾ݤƤ̾
    Ĥä̾򥯥饹̾Ȥޤ

      p foo = Class.new   # => #<Class:0x401b90f8>
      p foo.name          # => ""
      Foo = foo           #  p foo  "Foo" 
      Bar = foo
      p foo.name          # => "Bar"  ("Foo" ˤʤ뤫 "Bar" ˤʤ뤫)

    ruby 1.7 feature:
    ֥åͿ饹֥åΰϤ饹
    ΥƥȤǥ֥å¹Ԥޤξ饹
    ޤ

      klass = Class.new(super)
      klass.module_eval {|m| ... }
      klass

    ƱǤ֥åμ¹Ԥ Module#initialize Ԥޤ

