Merge topic 'add-join-function-in-system-tools'

6ccbfc12 SystemTools: Add a Join function

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Mathieu Westphal <mathieu.westphal@kitware.com>
Acked-by: Ben Boeckel <ben.boeckel@kitware.com>
Merge-request: !229