* acinclude.m4 (GNUPG_SYS_SYMBOL_UNDERSCORE): Use AS_MESSAGE_LOG_FD
instead of AC_FD_CC.
(GNUPG_CHECK_MLOCK): Use AC_LINK_IFELSE instead of AC_TRY_LINK.
Use AC_RUN_IFELSE instead of AC_TRY_RUN.
* configure.ac (AC_ISC_POSIX): Replace by AC_SEARCH_LIBS.
Use AC_USE_SYSTEM_EXTENSIONS instead of AC_GNU_SOURCE.
Use AS_HELP_STRING instead of AC_HELP_STRING.
(AC_TYPE_SIGNAL): Remove.
(AC_DECL_SYS_SIGLIST): Remove.
* m4/Makefile.am (EXTRA_DIST): Update.
* m4/onceonly.m4: Remove.
* m4/socklen.m4: Update from gnulib.
* m4/libtool.m4: Update from libgpg-error.
* m4/gpg-error.m4: Update from libgpg-error.
* m4/noexecstack.m4: Use AS_HELP_STRING instead of AC_HELP_STRING.