update startup scripts for NSM

fixes #6265 for GNU/Linux.

gtk2_ardour/ardour.sh.in

@@ -47,6 +47,12 @@ export ARDOUR_DATA_PATH=@DATADIR@
 export ARDOUR_CONFIG_PATH=@CONFDIR@
 export ARDOUR_DLL_PATH=@LIBDIR@
 
+#
+# NSM needs a path to this script
+#
+
+export ARDOUR_SELF="$0"
+
 #
 # VAMP has its own lookup path
 # 

tools/linux_packaging/ardour.sh.in

@@ -36,6 +36,10 @@ fi
 
 export ARDOUR_BUNDLED=true
 
+# NSM needs a path to this script
+export ARDOUR_SELF="$0"
+
+
 # this is edited by the build script to include relevant environment variables
 
 %ENV%

vst/ardourvst.in

@@ -11,6 +11,9 @@ export ARDOUR_DLL_PATH=@LIBDIR@
 export GTK_PATH=@LIBDIR@${GTK_PATH:+:$GTK_PATH}
 export LD_LIBRARY_PATH=@LIBDIR@${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
 
+# NSM needs a path to this script
+export ARDOUR_SELF="$0"
+
 exec wine @LIBDIR@/ardour-@VERSION@-vst.exe.so "$@"