vmstat and watch manpage slight fixes
vmstat - align wording with proc manpage to clarify ambiguities (rhbz#1796043) watch - manpage presumes ntp tools are present by default (which they're not on rpm and deb distros, rhbz#1583669)
vmstat - align wording with proc manpage to clarify ambiguities (rhbz#1796043) watch - manpage presumes ntp tools are present by default (which they're not on rpm and deb distros, rhbz#1583669)