ruby-dbi fix for 1.9.3

ruby-dbi.rb

module DBI
  class Row
    #
    # See Object#clone.
    #
    # #clone here, however, is a deep copy via Marshal.
    #
    def clone
      Marshal.load(Marshal.dump(self))
    end

    #
    # #dup is only a shallow copy
    #
    def dup
      row = self.class.allocate
      row.instance_variable_set :@column_types,  @column_types
      row.instance_variable_set :@convert_types, @convert_types
      row.instance_variable_set :@column_map,    @column_map
      row.instance_variable_set :@column_names,  @column_names
      # this is the only one we actually dup...
      row.instance_variable_set :@arr,           arr = @arr.dup
      row.instance_variable_set :@_dc_obj,       arr
      row
    end
  end
end

However I couldn't fix the encoding issue on 1.9.3 and switched to mysql2.