Fix make clean in docs

doc/Make-template

@@ -22,7 +22,7 @@
 all:	FORCE
 	@echo "making all in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) all"; \
 		( cd $$i; $(MAKE) $(MFLAGS) all ); \
 	    fi; \
@@ -32,7 +32,7 @@ all:	FORCE
 install:	FORCE
 	@echo "making install in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) install"; \
 		( cd $$i; $(MAKE) $(MFLAGS) install ); \
 	    fi; \
@@ -42,7 +42,7 @@ install:	FORCE
 clean:	FORCE
 	@echo "making clean in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) clean"; \
 		( cd $$i; $(MAKE) $(MFLAGS) clean ); \
 	    fi; \
@@ -55,7 +55,7 @@ veryclean:	clean
 depend:	FORCE
 	@echo "making depend in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) depend"; \
 		( cd $$i; $(MAKE) $(MFLAGS) depend ); \
 	    fi; \
@@ -65,7 +65,7 @@ depend:	FORCE
 lint:	FORCE
 	@echo "making lint in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) lint"; \
 		( cd $$i; $(MAKE) $(MFLAGS) lint ); \
 	    fi; \
@@ -75,7 +75,7 @@ lint:	FORCE
 5lint:	FORCE
 	@echo "making 5lint in `$(PWD)`"
 	@for i in *; do \
-	    if [ -d $$i -a $$i != "CVS" ]; then \
+	    if [ -d $$i -a $$i != "CVS" -a -f $$i/Makefile ]; then \
 		echo; echo "  cd $$i; $(MAKE) $(MFLAGS) 5lint"; \
 		( cd $$i; $(MAKE) $(MFLAGS) 5lint ); \
 	    fi; \