[FIX] fix editing one2many in some cases (web)

See issue #3964 for more detail.  Main problem was caused by commit
f0e331e005d8.  It set the key name+'__display' to false when reloading
a record for all field types, but it was only concerned with many2many.
Merge branch '7.0' of https://github.com/odoo/odoo into 7.0-win32