Add two testcases to TEST-71-HOSTNAME:
- testcase_tags exercises the new "hostnamectl tags" +/- prefix syntax
(add/remove, idempotency, the no-mixing rule, invalid input), the
AddAndRemoveTags() D-Bus method and the SetTags() Varlink method
(set/add/remove, explicit empty set, current-list basis).
- testcase_varlink_setters exercises the new SetHostname(),
SetStaticHostname(), SetPrettyHostname(), SetIconName(), SetChassis(),
SetDeployment() and SetLocation() Varlink methods, including resetting
values via null and rejection of invalid input.
Lennart Poettering
b3bad27735