Add a minimal C++ + QML shape example (showing a torus)

Change-Id: I04fcbdd28c5c05697fb04f6dfc809a2d8b8de5c7
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
Camera rotateAboutCenter fixed

Change-Id: I0fca99ea5e6bb74c97bca94c5fd082100a736dfb
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>