There wasn't a ton to do here (thanks mostly to Mike and Leigh keeping
this pretty up-to-date), but there were a few new cut and paste bugs,
and a few places where bugfixes or new features from libosload hadn't
quite made it across.

Maybe libosload_new hadn't been tested with vnodes, and at any rate, the
type/class-based loading mechanism couldn't find a libosload_new package
for them.  But the core of the support was there (libosload_virtnode).
So I added a libosload_pcvm class that sits atop libosload_virtnode.