def reset_bitfields column_name, *fields
      mask = self.class.reset_mask_for column_name, *fields
      self[column_name] = self[column_name] & mask
      save
    end
def reset_bitfields column_name, *fields
      mask = self.class.reset_mask_for column_name, *fields
      self[column_name] = self[column_name] & mask
      save
    end
Sets one or more bitfields to 0 within a column

 +reset_bitfield :column, :fields

 @example
   user.reset_bitfield :column, :daily, :monthly

 @param [ Symbol ] column     name of the column these fields are in
 @param [ Symbol ] field(s)   name of the field(s) to reset