Now resizing it won't produce weir overlaps of the widgets. Thanks to
Pelle Johansson for his help showing me how to do this.
(cherry picked from commit ef3498e92d13c82633fdbe8120396bfbe1e7489a)
Leaving xpr unflattened since we want modularity to replace that with xpc (XPluginComposite) at some point
(cherry picked from commit 48e6a75fbdd0fee86e364f02ace83f20b312a2b2)