The policy kit and HAL node device drivers both require a

DBus connection. The HAL device code further requires that
the DBus connection is integrated with the event loop and
provides such glue logic itself.

The forthcoming FirewallD integration also requires a
dbus connection with event loop integration. Thus we need
to pull the current event loop glue out of the HAL driver.

Thus we create src/util/virdbus.{c,h} files. This contains
just one method virDBusGetSystemBus() which obtains a handle
to the single shared system bus instance, with event glue
automagically setup.

daemon/Makefile.am

@@ -94,7 +94,7 @@ libvirtd_SOURCES = $(DAEMON_SOURCES)
 #-D_XOPEN_SOURCE=600 -D_XOPEN_SOURCE_EXTENDED=1 -D_POSIX_C_SOURCE=199506L
 libvirtd_CFLAGS = \
 	$(LIBXML_CFLAGS) $(GNUTLS_CFLAGS) $(SASL_CFLAGS) \
-	$(XDR_CFLAGS) $(POLKIT_CFLAGS) \
+	$(XDR_CFLAGS) $(POLKIT_CFLAGS) $(DBUS_CFLAGS) \
 	$(WARN_CFLAGS) \
 	$(COVERAGE_CFLAGS) \
 	-DQEMUD_PID_FILE="\"$(QEMUD_PID_FILE)\"" \
@@ -108,6 +108,7 @@ libvirtd_LDADD =					\
 	$(LIBXML_LIBS)					\
 	$(GNUTLS_LIBS)					\
 	$(SASL_LIBS)					\
+	$(DBUS_LIBS)					\
 	$(POLKIT_LIBS)
 
 if WITH_DTRACE_PROBES