build: require pkg-config for bootstrap

* .gnulib: Update to latest, for bootstrap fixes.
* bootstrap: Synchronize with upstream.
* bootstrap.conf: Add pkg-config pre-requisite.
* autogen.sh: Tweak wording message.
Reported by Justin Clift, and with feedback from Bruno Haible.

autogen.sh

@@ -49,7 +49,7 @@ if test "$t" = "$(cat $curr_status 2>/dev/null)" \
 else
     echo running bootstrap...
     ./bootstrap && bootstrap_hash > $curr_status \
-      || { echo "Failed to bootstrap gnulib, please investigate."; exit 1; }
+      || { echo "Failed to bootstrap, please investigate."; exit 1; }
 fi
 
 cd "$THEDIR"

bootstrap

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2010-09-30.17; # UTC
+scriptversion=2010-10-05.15; # UTC
 
 # Bootstrap this package from checked-out sources.
 
@@ -351,7 +351,7 @@ check_versions() {
       app=libtoolize
     fi
     # Honor $APP variables ($TAR, $AUTOCONF, etc.)
-    appvar=`echo $app | tr '[a-z]' '[A-Z]'`
+    appvar=`echo $app | tr '[a-z]-' '[A-Z]_'`
     test "$appvar" = TAR && appvar=AMTAR
     eval "app=\${$appvar-$app}"
     inst_ver=$(get_version $app)
@@ -374,7 +374,7 @@ check_versions() {
 print_versions() {
   echo "Program    Min_version"
   echo "----------------------"
-  printf "$buildreq"
+  printf %s "$buildreq"
   echo "----------------------"
   # can't depend on column -t
 }
@@ -392,10 +392,12 @@ if test $use_libtool = 1; then
 fi
 
 if ! printf "$buildreq" | check_versions; then
-  test -f README-prereq &&
-  echo "See README-prereq for notes on obtaining these prerequisite programs:" >&2
-  echo
-  print_versions
+  echo >&2
+  if test -f README-prereq; then
+    echo "See README-prereq for notes on obtaining the prerequisite programs" >&2
+  else
+    echo "Please install the prerequisite programs" >&2
+  fi
   exit 1
 fi
 
@@ -800,7 +802,7 @@ grep -E '^[	 ]*AC_CONFIG_HEADERS?\>' configure.ac >/dev/null ||
 
 for command in \
   libtool \
-  "${ACLOCAL-aclocal} --force -I m4" \
+  "${ACLOCAL-aclocal} --force -I m4 $ACLOCAL_FLAGS" \
   "${AUTOCONF-autoconf} --force" \
   "${AUTOHEADER-autoheader} --force" \
   "${AUTOMAKE-automake} --add-missing --copy --force-missing"

bootstrap.conf

@@ -150,6 +150,7 @@ git        1.5.5
 gzip       -
 libtool    -
 perl       5.5
+pkg-config -
 tar        -
 "