Redmine#5761: explicitly mark all commands as kept on return code = 0

(cherry picked from commit 44a203e0d340f39c9f0210ed292fd93ef39f11a3)

Conflicts:
	lib/3.7/cfe_internal.cf
	lib/3.7/common.cf
	lib/3.7/services.cf
	lib/3.7/vcs.cf