FancyZones should remember zones of child windows

[bzoz]

Summary of the new feature/enhancement

Right now only the main window is zoned - for example New Mail window in Outlook will not get snapped to a zone. We should keep track of zoned child windows.

Proposed technical implementation details (optional)

Right now we keep a map of program name -> zone. We should keep a map of (program name, is child?) -> zone. That would allow child windows (like new mail or documents in photoshop) also be assigned a zone.

We should probably wait for #368 before trying to implement this.

[bzoz]

Turns out Outlooks "New Mail" windows do not have parent window set. Recent fixes to FancyZones zoning make New Mail window behave as expected and we have a Photoshop related issue for zoning multiple windows of the same app.