cpp_sig_symbols.c, libpath.h and versiondat.h to BUILT_SOURCES
(libpath.h, versiondat.h): Replaced dependency on Makefile with
dependencies on $(srcdir)/Makefile.in
$(top_builddir)/config.status in order to avoid circularity.
* configure.in (GUILE_LIBS): New variable. Contains libraries
which libguile needs to be linked with. Substituted into
libpath.h.
* threads.m4 (threads_package): Don't add $LDFLAGS and $LIBS to
$cy_cv_threads_libs.
* ltconfig, ltmain.sh, config.sub, config.guess: Updated.
New automake: 1.3
* Makefile.in, aclocal.m4, configure: Regenerated.
* README: Mention new version numbers on libtool and automake.
* configure.in: AC_CHECK_FUNCS: add "system".
* simpos.c (scm_system): always define: use sysmissing if not
available. Check for HAVE_SYSTEM instead of _Windows (does
Windows lack system or does it have an unusable one?).
Check for error conditions -1 and 127. Use SCM_DEFER_INTS.
Let the argument be optional: if not supplied, call system(NULL).
* ports.c (scm_close_port): relax the type check from OPPORTP to
PORTP; closing a closed port is allowed.
