/usr/lib/libpowerdevilui.so.4 is in kde-workspace-bin 4:4.8.5-0ubuntu0.4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libpowerdevilui.so.4.8.0
/usr/lib/libpowerdevilui.so.4.8.0