fix interface_selector bug
If a view using this selector defines an `accepts` attribute, the
view should be selectable only if the entity is of one of the
accepted types (+need to consider schema inheritance)
.. -*- coding: utf-8 -*-API Reference=============Schema API----------Base Types~~~~~~~~~~Base types are defined as a set in yams.BASE_TYPES that includes:`String`, `Int`, `Float`, `Boolean`, `Date`, `Time`, `Datetime`,`Interval`, `Password`, `Bytes`.See `yams' API <http://lax.logilab.org/apidoc>`_Constraints~~~~~~~~~~~Constraints are defined in yams.constraints and include:`UniqueConstraint`, `SizeConstraint`, `RegexpConstraint`,`BoundConstraint`, `IntervalBoundConstraint`,`StaticVocabularyConstraint`, `MultipleStaticVocabularyConstraint`.See `yams' API <http://lax.logilab.org/apidoc>`_Views API---------See `yams' API <http://lax.logilab.org/apidoc>`_[WRITE ME]