Add business entity support.

Required SQL update:

CREATE TABLE IF NOT EXISTS `business_entity` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO business_entity (name) VALUES
  ('SARL'),
  ('EURL'),
  ('Particulier'),
  ('Auto Entreprise'),
  ('SAS'),
  ('SA')
  ;

ALTER TABLE webfinance_clients ADD COLUMN id_business_entity int(11);