Upgrade to newest Gnulib to help relocatable-prog on Mac OS X.

Upgrade to newest Gnulib to help relocatable-prog on Mac OS X.

--enable-relocatable currently fails on Mac OS X due to a link
error related to symbols that Gnulib is supposed to replace.
I see that Gnulib has the following commits, not previously in
PSPP, that mention related changes:

357d319 relocatable-lib: Move AC_LIBOBJ invocations to module description.
c2d8c01 relocatable-prog: Move AC_LIBOBJ invocations to module description.
325f131 relocatable-prog-wrapper: Fix possible link error.
886f850 relocatable-prog-wrapper: Assume strerror() exists.
02d4f86 relocatable-prog-wrapper: Update after module 'areadlink' changed.
d14f18b relocatable-prog-wrapper: Update after module 'areadlink' changed.
69c99f3 * lib/relocwrapper.c (_GL_USE_STDLIB_ALLOC, malloc): Likewise.
ef11bf4 * lib/relocatable.c (_GL_USE_STDLIB_ALLOC, malloc): Likewise.
10d90c8 * lib/progreloc.c (_GL_USE_STDLIB_ALLOC, malloc): Likewise.
4e51bc9 unictype/property-byname: Reduce the number of load-time relocations.
fb6aa6a relocatable-prog: fix link error

This commit updates PSPP to capture those changes.  It also
makes the changes recommended by Gnulib's NEWS.