build: Fix --disable-silent-rules. Thanks ng0!

* configure (main): Substitute V as string value.
* build-aux/trace.sh: Typo.  Fixes using V=0.
* build-aux/config.status.in (V): New substitute.
* build-aux/config.make.in (V): New substiute.

build-aux/config.make.in

@@ -40,6 +40,7 @@ PACKAGE:=@PACKAGE@
 PERL:=@PERL@
 TINYCC_PREFIX:=@TINYCC_PREFIX@
 VERSION:=@VERSION@
+V:=@V@
 
 abs_top_builddir:=@abs_top_builddir@
 abs_top_srcdir:=@abs_top_srcdir@

build-aux/config.status.in

@@ -40,6 +40,7 @@ PACKAGE="@PACKAGE@"
 PERL="@PERL@"
 TINYCC_PREFIX="@TINYCC_PREFIX@"
 VERSION="@VERSION@"
+V="@V@"
 
 abs_top_builddir="@abs_top_builddir@"
 abs_top_srcdir="@abs_top_srcdir@"

build-aux/trace.sh

@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
 
-if [ -z "$V" -o "$V0" = 0 ]; then
+if [ -z "$V" -o "$V" = 0 ]; then
     trace () {
         echo "  $1"
         shift

configure

@@ -557,7 +557,7 @@ Some influential environment variables:
                      ("@sysconfdir@" . ,sysconfdir)
 
                      ("@GUILE_EFFECTIVE_VERSION@" . ,(effective-version))
-                     ("@V@" . ,(if disable-silent-rules? 1 0))
+                     ("@V@" . ,(if disable-silent-rules? "1" "0"))
 
                      ("@AR@" . ,(or (file-name "ar" deps) ""))
                      ("@BASH@" . ,(or (file-name "bash" deps) ""))