[IMP] deduplicate code in handling of relational fields for exports listing
[IMP] deduplicate code in handling of relational fields for exports listing

havt/openerp-web,havt/openerp-web,havt/openerp-web,havt/openerp-web,akretion/openerp-web,akretion/openerp-web,akretion/openerp-web,havt/openerp-web