Add a tests user to run unprivileged tests as; use it in devel/kyua. This new user carries a generic 'tests' name because, even though it is only used by devel/kyua at this point, it could conceivably be used by other tools. Bump PORTREVISION of devel/kyua to 1. PR: ports/182891 Approved by: asomers (maintainer), bdrewery (ports), rpaulo (mentor)