Convert tabs to spaces.

I only used tabs before because that's what Visual Studio was producing.
Now I'm not using Visual Studio anymore...
Initial code for IDispatch implementation.

Still returning E_NOTIMPL.
CHello::QueryInterface now returns the IDispatch interface pointer.
Add client code for calling the IDispatch interface.

Currently doesn't work, because the component doesn't fully implement
the interface.
Fully implement CHello's IDispatch interface. I think...