Release v2.12.9.1

The following are the changes in this release:

    Fixed a typo typo in help/Makefile that caused the build of
    2.12.9.0 to fail in a number of cases.  Thanks to a report by
    <GitHub user balducci>.

    Pass form Makefile variables ${Q}, ${S}, ${E}, ${H} and ${V} down
    to all sub-directory Makefiles from the top level Makefile.

help/Makefile

@@ -176,11 +176,35 @@ T=
 
 # Makefile debug
 #
-# Q=@	do not echo internal makefile actions (quiet mode)
-# Q=	echo internal makefile actions (debug / verbose mode)
+# Q=@	do not echo internal Makefile actions (quiet mode)
+# Q=	echo internal Makefile actions (debug / verbose mode)
+#
+# H=@:	do not report hsrc file formation progress
+# H=@	do echo hsrc file formation progress
+#
+# S= >/dev/null 2>&1	slience ${CC} output during hsrc file formation
+# S=			full ${CC} output during hsrc file formation
+#
+# E= 2>/dev/null	slience command stderr during hsrc file formation
+# E=			full command stderr during hsrc file formation
+#
+# V=@:	do not echo debug statements (quiet mode)
+# V=@	do echo debug statements (debug / verbose mode)
 #
 #Q=
 Q=@
+#
+S= >/dev/null 2>&1
+#S=
+#
+E= 2>/dev/null
+#E=
+#
+#H=@:
+H=@
+#
+V=@:
+#V=@
 
 # standard tools
 #
@@ -637,8 +661,8 @@ builtin: builtin.top builtin.end ../func.c funclist.sed
 	${Q} ${SED} -n -f funclist.sed ../func.c > funclist.c
 	${Q} ${RM} -f funclist.o funclist${EXT}
 	${Q} ${LCC} ${ICFLAGS} -DFUNCLIST -I/usr/include \
-	    -I.. funclist.c -c 2>/dev/null
-	${Q} ${LCC} ${ILDFLAGS} funclist.o -o funclist${EXT}
+	    -I.. funclist.c -c ${S}
+	${Q} ${LCC} ${ILDFLAGS} funclist.o -o funclist${EXT} ${S}
 	${Q} ${RM} -f builtin
 	${Q} ${GREP} -v '^#'  builtin.top > builtin
 	${Q} ./funclist${EXT} | \