Import changes from coreutils for bootstrap script.

Import changes from coreutils for bootstrap script.

* build-aux/bootstrap (WGET_COMMAND): Remove code to set this variable.

bootstrap: uses rsync to download the .po files
* build-aux/bootstrap (po_download_command_format): New global.
(download_po_files): Use rsync.
(update_po_files): Don't remove .po files after download,
so future rsync runs can take advantage of the copies.

* build-aux/bootstrap (gnulib_tool): Make sha1sum check quietly.

Solve the unnecessary-.po-file-regeneration problem once and for all.
* build-aux/bootstrap (download_po_files): New function, renamed from
get_translations.  Now, downloads, but doesn't update LINGUAS.
(update_po_files): New function.

bootstrap: Ignore more.
* build-aux/bootstrap (symlink_to_dir): Add a directory name like
uniwidth to e.g., lib/.gitignore.
(slurp): Handle the sys_stat_.h -> sys mapping, too.

* build-aux/bootstrap: New setting: vc_ignore.
(insert_sorted_if_absent): Create $file if absent.
Adapt to new, possibly empty, list: $vc_ignore.

bootstrap: generate more ignorable names
* build-aux/bootstrap (slurp): When generating ignorable names,
also map .sin to .sed, .gperf to .c, and .y to .c.

2007-09-03  Jim Meyering  <jim@meyering.net>