SVGHMI: attempt to optimize for webkit, because of really slow style recompute in svg:use : "unlink clones" (as in inkscape) but stop deep-copy when meeting a widget, and create a new clone instead.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot URI_location="LOCAL://">
  <TargetType/>
  <Libraries Enable_SVGUI_Library="true" Enable_Python_Library="true"/>
</BeremizRoot>