Likewise fix default configuration to use SOCK_DGRAM and not SOCK_STREAM
as we currently do.

Add sha256 digest.

Rather than have the users replace syslog-ng.conf (which lately is
changing fairly frequently) and have them miss an important fix or
improvement, instead have them localize /etc/custom-logs.conf and
ship that as an empty file.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>