* Makefile.am (AUTOMAKE_OPTIONS): Require Automake 1.10 (or

later), which works better with systems that have a non-empty
$(EXEEXT).
(SUBDIRS): Drop intl.
(DISTCLEANFILES): Drop intl/plural.c.

* Throughout Makefile.am and the automake.mk files: Change
mkinstalldirs to $(MKDIR_P), to support the corresponding Automake
change.

* Smake (GNULIB_MODULES): Use gettext-h instead of gettext module.
(all): Don't create intl directory.
(gettextize): Don't use --intl flag.

* configure.ac: Require Autoconf 2.60 or later.  Use external
gettext.  Drop intl/Makefile from config files.