Start STONITH primitive resources

For some reason, sometimes, I see them not running after the cluster
creation. Since we're supposed to explicitly start all primitives, this
should work better.

(cherry picked from commit b154e3c43e670eccba25210421a30333ceeb8fba)
Merge pull request #133 from vuntz/start-stonith-roxy

[roxy] Start STONITH primitive resources