Branch b1_6

Exit on 'make sources' failure so that the rest of the build fails at the
correct time.

b=13026
i=mjmac
i=brian

build/autoMakefile.am.toplevel

@@ -29,7 +29,7 @@ sources: all-sources
 
 all-sources:
 	for dir in $(SOURCES_SUBDIRS) ; do \
-		$(MAKE) sources -C $$dir ; \
+		$(MAKE) sources -C $$dir || exit $$? ; \
 	done
 
 if LINUX