example program make now uses ross-config

doc/example/Makefile

-all: check example.o example
+ifndef CODESBASE
+$(error CODESBASE is undefined, see README.txt)
+endif
+ifndef CODESNET
+$(error CODESNET is undefined, see README.txt)
+endif
+ifndef ROSS
+$(error ROSS is undefined, see README.txt)
+endif
 
-CFLAGS= -Wall
-CC=mpicc
+# ross conflates CFLAGS with CPPFLAGS, so use just this one
+override CPPFLAGS += $(shell $(ROSS)/bin/ross-config --cflags) -I$(CODESBASE)/include -I$(CODESNET)/include/codes
+CC = $(shell $(ROSS)/bin/ross-config --cc)
+LDFLAGS = $(shell $(ROSS)/bin/ross-config --ldflags) -L$(CODESBASE)/lib -L$(CODESNET)/lib
+LDLIBS = $(shell $(ROSS)/bin/ross-config --libs) -lcodes-net -lcodes-base 
 
-check: check-env
-	@echo CODESBASE: $(CODESBASE)
-	@echo CODESNET: $(CODESNET)
-	@echo ROSS: $(ROSS)
-	
-example.o: example.c
-	$(CC) -c $(CFLAGS) -I$(ROSS)/include -I$(CODESBASE)/include -I$(CODESNET)/include example.c 
+example: example.c
 
-example: example.o
-	$(CC) $(CFLAGS) example.o -o example -L$(ROSS)/lib -lROSS -lm -L$(CODESBASE)/lib -lcodes-base -L$(CODESNET)/lib -lcodes-net
+#$(CC) $(ROSS_CPPFLAGS) $(CPPFLAGS) $(CFLAGS) $(ROSS_LDFLAGS) $^ -o $@ -L$(ROSS)/lib -lROSS -lm -L$(CODESBASE)/lib -lcodes-base -L$(CODESNET)/lib -lcodes-net
 
 check-env:
 ifndef CODESBASE