PATCH: SetParent optimization

[Ann and Jason Edmeades]

> Probably SetWindowLong(GWL_HWNDPARENT) should not do a full SetParent,
> but just set the window owner. Looks like this needs more testing
> under Windows to find out exactly what it's supposed to do.

Interestingly I took out that SetParent call as a hack to get beyond bug#825
which is exactly what VB is doing for 'modal' windows (setting
GWL_HWNDPARENT)
which basically means modal windows become unusable.

Jason