[FIX] incorrect clearing of default values on selection fields in search view
[FIX] incorrect clearing of default values on selection fields in search view

and simplification of the same on basic fields

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