Remove references to 'olivneh' account from node defs

'olivneh' is now disabled; I use 'ori'. Because I have files in my home
directory on some of these systems, I am not purging the account from the
systems it was on, merely removing it from the manifest. I also removed
groups::wikidev from vanadium, professor, nickel & tungsten, where it was added
as part of granting me access. No other accounts in the wikidev group were
specified for these systems.

Change-Id: Ic90a73af0df6f608085721866b46d1e431eaed47