Merge topic 'update-kwsys'

0e47391400 bootstrap: Update for new KWSys configuration option
fb15c27562 Merge branch 'upstream-KWSys' into update-kwsys
0225b05afe KWSys 2019-04-17 (c42b92f0)

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !3242