[IMP] implement add and remove node functionality in vieweditor.
[IMP] implement add and remove node functionality in vieweditor.

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