Client code usually calls get_filters() to get the list of filters for
a particular model, and then create_or_replace() to manage these filters.
In both cases a new @is_default attribute is now available - the idea
being that the default filter is always applied when a view is newly
opened. Global (user_id = False) filters are replaced by user-specific
filters when there are any.
bzr revid: odo@openerp.com-20121109140828-gpuifdjwrmefg5n2
91e2d25cdd