Revert "no need for depending on build library ("blib")"

This reverts commit 9dc2515d7e.

I want "make" to actually build something.

src/Makefile

 # If invoked with no build target, print out a helpfully suggestive
 # message.
 #
-noargs :
+noargs : blib
 	@echo '===================================================='
 	@echo
 	@echo ' *** WARNING: THE INSTRUCTIONS BELOW DO NOT FULLY WORK YET !!!  ***'