BUILD: Detect libsystemd-daemon or libsystemd Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

BUILD: Fix detection of systemd The macro AM_COND_IF must be called after AM_CONDITIONAL Otherwise it will consider that condition is true. As a result of this the header file config.h had defined macro HAVE_SYSTEMD on all platforms Our macro AM_CHECK_SYSTEMD was removed becuase it was needed in src/external/systemd.m4 and should not be invoked later in configure.ac Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

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

BUILD: Repair dependecies on deprecated libraries Modules libsystemd-journal and libsystemd-login are deprecated and "libsystemd" should be used instead of them. Resolves: https://fedorahosted.org/sssd/ticket/2733 Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

Add journald support

Do not set HAVE_SYSTEMD_LOGIN if libsystemd-login is not available Even if HAVE_SYSTEMD_LOGIN is set to 0 #ifdef will still see it as defined.

util: Use systemd-login to check user sessions Use systemd-lgin in preference to check if the user is logged in or not. Fall back to the old method if no systemd-login support is available at compile time or if it returns a fatal error, and can't determine the status of the user on its own. This will allow to consider a user really active (in order to reuse or refresh crdentials) only if it really is logged into the system, and not just if one of the user's processes is stuck around. Resolves: https://fedorahosted.org/sssd/ticket/2084

Provide a configuration option to use systemd unit file https://fedorahosted.org/sssd/ticket/837