Commit 0c6ad476 updated gnulib, which rearranged some of the
conditions in gnulib wrapper headers such that compilation
started failing on BSD systems when the normal system <unistd.h>
tried to include another system header but instead got a
gnulib wrapper header in an incomplete state; this is because
gnulib headers only work if <config.h> is included first.

Commit b6f78259 papered over the symptoms of that by including
<config.h> in all the examples.  But this logic is backwards -
if our examples are truly meant to be stand-alone, they should
NOT depend on how libvirt was configured, and should NOT
depend on the gnulib fixes for system quirks.  In particular,
if an example does not need to link against libgnulib.la,
then it also does not need to use -Ignulib in its compile
flags, and likewise does not need to include <config.h> since
none of the gnulib wrapper headers should be interfering.

So, revert (most of) b6f78259 (except for the bogus pre-patch
use of "config.h" in admin/logging.c: if config.h is included,
it should be via <> rather than "", and must be before any
system headers); then additionally nuke all mention of
<config.h>, -Ignulib, and -llibgnu.la, making all of the
examples truly standalone.
Signed-off-by: NEric Blake <eblake@redhat.com>
Acked-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Since gnulib commit 6954995d unistd.h is included via stdlib.h
on BSD systems, which requires config.h to be included first.

Add config.h to the files that use it.

Part of this commit reverts commit 6ee918deSigned-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

In 60046283 we've tried to remove Author(s): lines
from comments at the beginning of our source files. Well, in some
files while we removed the "Author" line we did not remove the
actual list of authors.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

Using one Makefile per example subdirectory essentially serializes 'make'
calls. Convert to one example/Makefile that builds and distributes
all the subdir files. This reduces example/ rebuild time from about 5.8
seconds to 1.5 seconds on my machine.

One slight difference is that we no longer ship Makefile.am with the
examples in the rpm. This was virtually useless anyways since the Makefile
was very specific to libvirt infrastructure, so wasn't generically
reusable anyways.

Tested with 'make distcheck' and 'make rpm'

This commit adds a new example to illustrate peer to
peer domain migration with virDomainMigrateToURI.
Signed-off-by: NSahid Orentino Ferdjaoui <sahid.ferdjaoui@cloudwatt.com>