nproc: A new program to count the available processors

* AUTHORS: Add my name.
* NEWS: Mention it.
* README: Likewise.
* bootstrap.conf (gnulib_modules): Add nproc.
* doc/coreutils.texi (nproc invocation): Add nproc info.
* man/Makefile.am (nproc.1): Add dependency.
* man/nproc.x: New template.
* man/.gitignore: Ignore generated man page.
* po/POTFILES.in: Add src/nproc.c.
* src/.gitignore: Exclude nproc.
* src/Makefile.am (EXTRA_PROGRAMS): Add nproc.
* src/nproc.c: New file.
* tests/Makefile.am (TESTS): Add misc/nproc-{avail,positive}.
* tests/misc/nproc-avail: New file.
* tests/misc/nproc-positive: New file.

AUTHORS

@@ -51,6 +51,7 @@ mv: Mike Parker, David MacKenzie, Jim Meyering
 nice: David MacKenzie
 nl: Scott Bartram, David MacKenzie
 nohup: Jim Meyering
+nproc: Giuseppe Scrivano
 od: Jim Meyering
 paste: David M. Ihnat, David MacKenzie
 pathchk: Paul Eggert, David MacKenzie, Jim Meyering