CXTPTaskDialog relative positioning bug

I noticed that CXTPTaskDialog does not properly position itself relative to the parent window if you don't actually specify a parent window in the constructor. I looked through the code, and the main application window is being used as the parent, but it's not being used to perform relative positioning of the dialog.

The fix for this is very simple. Just add the following line of code at the beginning of the CXTPTaskDialogClient::CreateClient method:

m_pConfig->hwndParent = GetParent()->GetSafeHwnd();

This syncs the internal hwndParent parent field of the CXTPTaskDialogClient class with the real parent of the dialog.

With this fix the CXTPTaskDialog will now behave more similarly to the standard CDialog class.

Hopefully this fix can be included in the next release.