[FIX] mail: sort messages by id instead of date, clientside
[FIX] mail: sort messages by id instead of date, clientside

sorting by date was not sufficient, some messages had exactly the same
date, which had some subtle issues in the client interface.

microcom/odoo,laslabs/odoo,sysadminmatmoz/OCB,bplancher/odoo,stephen144/odoo,ygol/odoo,hip-odoo/odoo,laslabs/odoo,dfang/odoo,microcom/odoo,storm-computers/odoo,hip-odoo/odoo,ygol/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,stephen144/odoo,dfang/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,microcom/odoo,bplancher/odoo,laslabs/odoo,ygol/odoo,laslabs/odoo,bplancher/odoo,stephen144/odoo,optima-ict/odoo,sysadminmatmoz/OCB,dfang/odoo,optima-ict/odoo,optima-ict/odoo,hip-odoo/odoo,Elico-Corp/odoo_OCB,sysadminmatmoz/OCB,laslabs/odoo,bplancher/odoo,sysadminmatmoz/OCB,optima-ict/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,ygol/odoo,Elico-Corp/odoo_OCB,ygol/odoo,bplancher/odoo,dfang/odoo,storm-computers/odoo,sysadminmatmoz/OCB,hip-odoo/odoo,optima-ict/odoo,storm-computers/odoo,Elico-Corp/odoo_OCB,microcom/odoo,storm-computers/odoo,microcom/odoo,optima-ict/odoo,hip-odoo/odoo,bplancher/odoo,ygol/odoo,storm-computers/odoo,hip-odoo/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,dfang/odoo,ygol/odoo,laslabs/odoo,microcom/odoo,dfang/odoo