* configure.in: Due to a bug in autoconf-2.13 implementation of

* configure.in: Due to a bug in autoconf-2.13 implementation of
AC_SUBST, `AC_SUBST(FILE)' can never work.  Use MAGIC as the
holder of the command to run in file_magic_cmd instead.
* ltconfig.in: s/FILE/MAGIC/g.
* libtool.m4 (AC_PROG_LIBTOOL): set MAGIC in the environment when
calling ltconfig.
(AC_PATH_MAGIC):  renamed from AC_PATH_FILE.
(AC_PATH_TOOL_PREFIX):  s/FILE/MAGIC/g.  Also set file_magic_cmd
to '${MAGIC}' so that make can grok it.
* Makefile.am (libtool):
(clibtool): ditto.