Accept unknown kwargs in taurus mixin class constructors
BaseConfigurableClass, TaurusBaseComponent, TaurusBaseWidget and TaurusBaseWritableWidget are used as mixin classes, mostly with QtObject-derived classes.
In order to support cooperative multiple inheritance with the super() statement, they need to be able to accept unknown kwargs in their constructors. See: https://www.riverbankcomputing.com/static/Docs/PyQt5/multiinheritance.html
This allows the following pattern:
class Foo(QObject, TaurusBaseComponent):
def __init__(self, bar=None, **kwargs):
super(Foo, self).__init__(**kwargs) # <- py2+py3
# super().__init__(**kwargs) # <- py3 only
self.bar = bar