guest agent: qemu-ga daemon

This is the actual guest daemon, it listens for requests over a
virtio-serial/isa-serial/unix socket channel and routes them through
to dispatch routines, and writes the results back to the channel in
a manner similar to QMP.

A shorthand invocation:

  qemu-ga -d

Is equivalent to:

  qemu-ga -m virtio-serial -p /dev/virtio-ports/org.qemu.guest_agent.0 \
          -f /var/run/qemu-ga.pid -d

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
diff --git a/configure b/configure
index 796f706..f9be709 100755
--- a/configure
+++ b/configure
@@ -2532,6 +2532,7 @@
   tools="qemu-img\$(EXESUF) qemu-io\$(EXESUF) $tools"
   if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then
       tools="qemu-nbd\$(EXESUF) $tools"
+      tools="qemu-ga\$(EXESUF) $tools"
     if [ "$check_utests" = "yes" ]; then
       tools="check-qint check-qstring check-qdict check-qlist $tools"
       tools="check-qfloat check-qjson $tools"