Blender Git Loki

Bugfix for the render window not popping to the front when it already existed,
under linux / x11 / KDE.

The new behaviour in 2.34, not recreating the render window on re-render,
revealed that raising windows did not work under some window managers. Now the
"net wm extensions" are used if available, otherwise it will work the same way
as before (e.g. Gtk+ does this as well).

More info:
http://www.freedesktop.org/Standards/wm-spec