[IMP] regroup all __get_default_$name_view calls into a single parametric getattr
[IMP] regroup all __get_default_$name_view calls into a single parametric getattr

Also rename __get_default_ to _get_default_ so it can be found by getattr

akretion/openerp-server,akretion/openerp-server,akretion/openerp-server