remove sysstat & pidstat

dstat is far cleaner for getting results out of the environment,
and covers the bulk of our use cases for sysstat and pidstat with
a much better ui.

devstack is allowed to be opinionated, so become opinionated here.

Change-Id: I21ec96339dcd704098512fdafd896738f352962d
Merge "remove sysstat & pidstat"