replace pref html file with xul file

mailnews/compose/prefs/resources/content/MANIFEST

@@ -17,5 +17,5 @@
 #
 
 pref-messages.xul
-pref-copiesfolders.html
+pref-copiesfolders.xul
 pref-formatting.xul

mailnews/compose/prefs/resources/content/Makefile.in

@@ -30,7 +30,7 @@ SAMPLES_DIR = $(DIST)/bin/chrome/messengercompose/content/default
 
 EXPORT_RESOURCE_SAMPLES = \
 	$(srcdir)/pref-messages.xul \
-	$(srcdir)/pref-copiesfolders.html \
+	$(srcdir)/pref-copiesfolders.xul \
 	$(srcdir)/pref-formatting.xul \
 	$(NULL)
 

mailnews/compose/prefs/resources/content/makefile.win

@@ -22,10 +22,10 @@ include <$(DEPTH)\config\rules.mak>
 
 install:: 
 	$(MAKE_INSTALL) pref-messages.xul $(DIST)\bin\chrome\messengercompose\content\default
-	$(MAKE_INSTALL) pref-copiesfolders.html $(DIST)\bin\chrome\messengercompose\content\default
+	$(MAKE_INSTALL) pref-copiesfolders.xul $(DIST)\bin\chrome\messengercompose\content\default
 	$(MAKE_INSTALL) pref-formatting.xul $(DIST)\bin\chrome\messengercompose\content\default
 
 clobber::
 	rm -f $(DIST)\chrome\messengercompose\content\default\pref-messages.xul
-	rm -f $(DIST)\chrome\messengercompose\content\default\pref-copiesfolders.html
+	rm -f $(DIST)\chrome\messengercompose\content\default\pref-copiesfolders.xul
 	rm -f $(DIST)\chrome\messengercompose\content\default\pref-formatting.xul