+2012-05-28 Paul Eggert <eggert@cs.ucla.edu>
+
+ Make 'configure' a bit smaller and faster.
+ * configure.in (INSTALL_INFO): Set it with one call to
+ AC_PATH_PROG, not three.
+ (PKG_CONFIG): Hoist this out of PKG_CHECK_MODULES, since it's
+ so likely that it'll be needed.
+ (AC_CHECK_HEADERS_ONCE): Prefer to AC_CHECK_HEADERS where either works.
+ (AC_PROG_MAKE_SET): Remove; Automake does this.
+ (sysinfo): Do not check for this function, as it's never used.
+ (tzset): Check for this function just once.
+ * m4/manywarnings.m4: Sync from gnulib, incorporating the following:
+ 2012-05-27 manywarnings: remove duplicate -Wmultichar entry
+