[FIX] auth_ldap: remove insignificant spaces in login

strip spaces from user name as they will probably be ignored by ldap's search (rfc4518)
Fixes #2865
[FIX] account_anglo_saxon: avoid two box purchase_ok field

as account_anglo_saxon depends from purchase and purchase already adds the field purchase_ok
Fixes #2630
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64