Split args for init

[r-spiewak]

Add function (and mixin and decorator) to split args for inits.

Example:

    class Child(Parent1, Parent2):
        def __init__(self, *args, **kwargs):
            self.split = split_args_for_inits_strict_kwargs(
                type(self), args, kwargs
            )
            Parent1.__init__(
                self, *self.split[Parent1]["args"], **self.split[Parent1]["kwargs"]
            )
            Parent2.__init__(
                self, *self.split[Parent2]["args"], **self.split[Parent2]["kwargs"]
            )
            self._init_leftovers = self.split["leftovers"]

[r-spiewak]

Example is now one of the following three:

    class Child(Parent1, Parent2):
        def __init__(self, *args, **kwargs):
            apply_split_inits(self, args=args, kwargs=kwargs)

or (using the mixin class)

    class Child(SplitInitMixin, Parent1, Parent2):
        def __init__(self, *args, **kwargs):
            super().__init__(args=args, kwargs=kwargs)

or (using the decorator)

    @auto_split_init
    class Child(Parent1, Parent2):
        def __init__(self, *args, **kwargs):
            pass