Added rule to use CXX to compile .cc files to .o files. Needed for assign.

GNUmakerules

@@ -62,9 +62,12 @@ vpath %.c $(SRCDIR)
 %.o: %.c
 	$(CC) -c -o $@ $(CFLAGS) $<
 
+%.o: %.cc
+	$(CXX) -c -o $@ $(CXXFLAGS) $<
+
 #
 # Rules to regen configure written files.
 #
 %: %.in
 	@echo "Regenerating $@"
-	cd $(OBJDIR) && CONFIG_FILES=$(SUBDIR)/$@ config.status
\ No newline at end of file
+	cd $(OBJDIR) && CONFIG_FILES=$(SUBDIR)/$@ config.status