$NetBSD$

Make pulseaudio optional.

--- unix/vm-sound-pulse/config.cmake.orig	2009-09-14 21:09:24.000000000 +0000
+++ unix/vm-sound-pulse/config.cmake
@@ -1 +1,7 @@
 PLUGIN_REQUIRE_LIBRARY (PULSE pulse-simple)
+
+CHECK_LIBRARY_EXISTS (pulse-simple pa_stream_new "" HAVE_PULSE)
+IF (NOT HAVE_PULSE)
+  PLUGIN_DISABLE ()
+ENDIF ()
+
