Add a growl (http://growl.info/) notification plugin (most of code from msn.c)

It is built by default since it sends notifications to network (perhaps
we should only build it on macos).

msn.c: should fix a refcount issue (*not tested*)

configure.ac

@@ -1423,6 +1423,17 @@ then
   AC_DEFINE(ENABLE_VLM, 1, Define if you want the VideoLAN manager support)
 fi
 
+dnl
+dnl Growl notification plugin
+dnl
+AC_ARG_ENABLE(growl,
+  [  --enable-growl         growl notification plugin (default enabled)])
+AS_IF([test "${enable_growl}" != "no"], [
+    VLC_ADD_PLUGINS([growl])
+  ]
+)
+
+
 dnl
 dnl TLS/SSL
 dnl

modules/misc/Modules.am

@@ -11,3 +11,4 @@ SOURCES_vod_rtsp = rtsp.c
 SOURCES_gnutls = gnutls.c
 SOURCES_svg = svg.c
 SOURCES_msn = msn.c
+SOURCES_growl = growl.c

modules/misc/msn.c

@@ -196,6 +196,7 @@ static int ItemChange( vlc_object_t *p_this, const char *psz_var,
     free( psz_album );
 
     SendToMSN( psz_tmp );
+    vlc_object_release( p_input );
 
     return VLC_SUCCESS;
 }