* .gitmodules: New file; manage gnulib as a submodule. For future
compatibility with the "bootstrap" script, keep the gnulib
submodule in the gnulib directory (instead of the gnulib-git
directory as before). This means we need to find a new directory
for the output of gnulib-tool; we will use "gl" for that.
* import-gnulib.sh (do_checkout): Replace with do_submodule.
(do_submodule): initialise and configure the gnulib module.
(main): call do_submodule instead of do_checkout. Don't call
move_cvsdir, it's obsolete.
(move_cvsdir): delete
* Makefile.am (SUBDIRS): Rename gnulib to gl.
(ACLOCAL_AMFLAGS): Likewise.
(findutils-check-smells): Rename gnulib-git to gnulib.
* .gitignore: Rename gnulib to gl.