system-source: Use /dev/log on HP-UX

Using /dev/pipe on HP-UX was a mistake, use /dev/log instead, as the
original shell script did.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
autogen.sh: Use --copy for libtoolize and automake

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
afstreams: Fix the CPPFLAGS for the module

It should look for files under both ${top_srcdir} and ${top_builddir},
not twice at the same place.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
afstreams: Migrate to new, working APIs

The afstreams module has been broken for more than a year, this patch
brings it back from the dead by migrating it to newer APIs and all.

Based on a patch by Balazs Scheidler <bazsi@balabit.hu>.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>