the former has been deprecated and does not work on newer autoconf
versions.
# Checks for libraries.
# Checks for header files.
-AM_CONFIG_HEADER(config.h)
-AM_CONFIG_HEADER(json_config.h)
+AC_CONFIG_HEADER(config.h)
+AC_CONFIG_HEADER(json_config.h)
AC_HEADER_STDC
AC_CHECK_HEADERS(fcntl.h limits.h strings.h syslog.h unistd.h [sys/cdefs.h] [sys/param.h] stdarg.h locale.h)
AC_CHECK_HEADER(inttypes.h,[AC_DEFINE([JSON_C_HAVE_INTTYPES_H],[1],[Public define for json_inttypes.h])])