Fix dispatch handling for properties

[the-snork]

See the following pseudo code (IDL):

[...]
interface IFoo : IDispatch
{
    HRESULT Bar();
}

interface IHolder
{
    [propget]HRESULT Foo
    {
        [out, retval]IFoo **foo
    };
}

When importing above with makepy, the following fails in Python

foo = holder.Foo
foo.Bar()

due to member not found, while this works:

foo = holder.Foo
fooWrapped = IFoo(foo)
fooWrapped.Bar()

This pull request is for enabling the first variant, too.

The problem is the intermediate dynamic wrapper.

[mhammond]

wouldn't this be slightly better rolled up in the above seeing that it's identical? A changelog entry would be great too!

[the-snork]

better like this?

[mhammond]

thanks