sssctl: use systemd D-Bus API If systemd is used we leverage it's D-Bus API instead of running systemctl. Resolves: https://fedorahosted.org/sssd/ticket/3056 Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

sssctl: use talloc with sifp This way we completely move D-Bus memory management to talloc and we reduce number of code lines needed to send and receive reply. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com> Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

sssctl: Consistent commands naming Use TOPIC-ACTION pattern for sssctl command names. Resolves: https://fedorahosted.org/sssd/ticket/3087 Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

sssctl: Add config-check command Fixes: https://fedorahosted.org/sssd/ticket/2269 sssctl sconfig-check command allows to call SSSD config file validators on demand. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

TOOLS: Add the upgrade-cache command Allows to upgrade the cache using the sssctl tool, which might be useful e.g. in RPM %post scripts. Reviewed-by: Sumit Bose <sbose@redhat.com>

sssctl: new tool Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>