TaskDialog implementation

[Juan Lang]

Hi Patrick,

> As this is quite a big amount of work, I would like to have some
> guidance (what must I do to be sure it is accepted) so that I do not end
> up doing all that for nothing - starting by knowing why my patch from
> yesterday was not accepted (what did I do wrong).

The patch was marked as "Pending."  That usually means Alexandre's
waiting for something, e.g. for you to fix something obvious, or to
see what else you're planning to do.  Since you say the patch is
preparatory work, it doesn't make much sense to go in unless the
remaining patches are also to go in, so I'd suggest sending at least
another patch to show where you're going with it.

Regarding splitting, sometimes it's useful to introduce code that will
only be removed later.  I know this isn't the usual advice, but if you
introduce a new implementation of something, sometimes a stub
implementation can appear first.  E.g., if it's an interface you're
implementing, introduce an implementation that does nothing but return
E_NOTIMPL from each method.  Then one by one introduce implementation
for each function.

Hope that helps,
--Juan