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
Enable threaded mode by default

With this patch, threaded(yes) becomes the default. In case one wants to
turn it off, threaded(no) must be set.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
afsocket: Consider afsocket-systemd-override.h a source file too

In order to be able to build from a make dist tarball, we need to ship
afsocket-systemd-override.h too, so add it to the list of afsocket
sources.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>