maint: fix typos in test comments and old ChangeLog files

Culprits identified and fixed automatically using these commands:
git ls-files|misspellings -f -|perl -nl \
  -e '/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/ or next;' \
  -e '($file,$n,$l,$r)=($1,$2,$3,$4); $q="'\''"; $r=~s/$q/$q\\$q$q/g;'\
  -e 'print "sed -i $q${n}s!$l!$r!$q $file"' | bash
using http://github.com/lyda/misspell-check
* old/fileutils/ChangeLog: Fix typos.
* old/textutils/ChangeLog: Likewise.
* tests/misc/truncate-fail-diag: Likewise.
stat,tail: recognize new file system type: panfs

* src/stat.c (human_fstype) [__linux__]: Add a 'case' for the new
remote file system type: panfs (0xAAD7AAEA).
* NEWS (New features): Mention stat -f.
(Bug fixes): Mention it for tail -f.
Reported by Travis Gummels in http://bugzilla.redhat.com/827199
head: with --lines=-N (-n-N) reset file pointer on seekable input

* src/head.c (elide_tail_lines_seekable): Reset file pointer
after printing up to an end-relative line-counted offset.
Anoop Sharma reported the problem and suggested the fix.
* tests/misc/head-pos: Add coverage via a very similar, existing test.
Also add coverage for a previously untested block of code.
* tests/misc/head-elide-tail ($READ_BUFSIZE): Update to 8192, to
match the value of BUFSIZ I see today on Fedora 17/x86_64 (unrelated
to this fix).
* NEWS (Bug fixes): Mention it.

Improved-by: Pádraig Brady
maint: mark new diagnostic for translation

* src/head.c (elide_tail_lines_seekable): Mark new diagnostic.
I will look at the results of "make syntax-check", I will look...
maint: detect a new type of duplicate in THANKS.in

* cfg.mk (sc_THANKS_in_duplicates): New rule.
su: remove program (util-linux is now the best source for it)

* README: Omit "su" from list of programs.
* src/su.c: Remove file.
* src/Makefile.am: Remove su-related rules and variables.
* tests/misc/su-fail: Remove test.
* tests/Makefile.am (TESTS): Remove misc/su-fail.
* tests/misc/invalid-opt: Remove su-related code.
* src/.gitignore: Remove su.
* man/su.x: Remove file.
* man/Makefile.am (su.1): Remove rule.
* po/POTFILES.in: Remove su.c from the list.
* TODO: Remove ancient entry.
* NEWS (Changes in behavior): Mention it.
* doc/coreutils.texi: Remove su-related description.
* AUTHORS: Remove su.
* m4/lib-check.m4 (cu_LIB_CHECK): Remove file/macro.
* configure.ac: Remove su-related code and sole use of cu_LIB_CHECK.
* scripts/git-hooks/commit-msg: Remove su from this list, too.
Merge branch 'master' into automake-ng

* master:
  su: remove program (util-linux is now the best source for it)
  maint: detect a new type of duplicate in THANKS.in
  maint: mark new diagnostic for translation
  head: with --lines=-N (-n-N) reset file pointer on seekable input
  stat,tail: recognize new file system type: panfs
  maint: fix typos in test comments and old ChangeLog files

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>
fixup: bugs in recent edits to man/Makefile.am

* man/Makefile.am (get-c-for-man): New GNU make function.
Use it when dynamically defining dependencies for generated manpages,
increasing clarity, reducing brittleness, and removing a botched usage
of the $(filter-out) built-in.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>