service-management: add service_management_get_type() function

Signed-off-by: Tibor Benke <ihrwein@gmail.com>
afsocket: add systemd-syslog() source

Signed-off-by: Tibor Benke <ihrwein@gmail.com>
system-source: change to systemd-syslog() source, when the running init system is systemd

Signed-off-by: Tibor Benke <ihrwein@gmail.com>
Merge pull request #184 from ihrwein/f/add-systemd-syslog-source

F/add systemd syslog source