doc,maint: fix use of "i.e." in documentation and comments

To align with all other places (and correct grammar), change all
upper-case "I.E." to "I.e.".  Furthermore, ensure that "i.e." is
followed by a comma.  Finally, ensure to use a double-space before
"I.e.," at the beginning of a sentence.

The following was used to change all offending uses (apart from
old ChangeLog files):

  $ git grep -liF 'i.e.' \
      | xargs sed -i \
            -e 's/I\.E\./I.e./g' \
            -e 's/\. \(I\.e\.\)/.  \1/g' \
            -e 's/\([Ii]\.e\.\)\( \)/\1,\2/g' \
            -e 's/\([Ii]\.e\.\)$/\1,/g'

* cfg.mk (sc_prohibit_uppercase_id_est): Add new rule.
(sc_ensure_double_space_after_dot_before_id_est): Likewise.
(sc_ensure_comma_after_id_est): Likewise.
(old_NEWS_hash): Refresh hash via "make update-NEWS-hash".
* NEWS: Change use of "id est" abbreviation via the above command.
* README: Likewise.
* README-prereq: Likewise.
* doc/coreutils.texi: Likewise.
* gl/lib/rand-isaac.c: Likewise.
* gl/lib/tempname.c.diff: Likewise.
* man/stdbuf.x: Likewise.
* src/cat.c: Likewise.
* src/copy.c: Likewise.
* src/copy.h: Likewise.
* src/cp.c: Likewise.
* src/cut.c: Likewise.
* src/dd.c: Likewise.
* src/df.c: Likewise.
* src/fiemap.h: Likewise.
* src/longlong.h: Likewise.
* src/ls.c: Likewise.
* src/numfmt.c: Likewise.
* src/pr.c: Likewise.
* src/shred.c: Likewise.
* src/shuf.c: Likewise.
* src/split.c: Likewise.
* tests/Coreutils.pm: Likewise.
* tests/df/df-symlink.sh: Likewise.
* tests/df/skip-rootfs.sh: Likewise.
* tests/init.sh: Likewise.
* tests/ls/color-norm.sh: Likewise.
* tests/misc/basename.pl: Likewise.
* tests/misc/ls-misc.pl: Likewise.
* tests/misc/md5sum-bsd.sh: Likewise.
* tests/misc/shred-exact.sh: Likewise.
* tests/misc/sort.pl: Likewise.
* tests/misc/stdbuf.sh: Likewise.
* tests/misc/tac-continue.sh: Likewise.
* tests/rm/r-root.sh: Likewise.
* tests/tail-2/symlink.sh: Likewise.

2 files changed, 2 insertions, 2 deletions

diff --git a/tests/df/df-symlink.sh b/tests/df/df-symlink.sh
index 44f954134..b59309788 100755
--- a/tests/df/df-symlink.sh
+++ b/tests/df/df-symlink.sh
@@ -31,7 +31,7 @@ compare exp out || fail=1
 # Ensure we output the same values for device nodes and '.'
 # This was not the case in coreutil-8.22 on systems
 # where the device in the mount list was a symlink itself.
-# I.E. '.' => /dev/mapper/fedora-home -> /dev/dm-2
+# I.e., '.' => /dev/mapper/fedora-home -> /dev/dm-2
 df --out=source,target '.' > out || fail=1
 compare exp out || fail=1
 
diff --git a/tests/df/skip-rootfs.sh b/tests/df/skip-rootfs.sh
index c42253dc3..a3b68e9b2 100755
--- a/tests/df/skip-rootfs.sh
+++ b/tests/df/skip-rootfs.sh
@@ -23,7 +23,7 @@ df || skip_ "df fails"
 
 # Verify that rootfs is in mtab (and shown when the -a option is specified).
 # Note this is the case when /proc/self/mountinfo is parsed
-# rather than /proc/mounts.  I.E. when libmount is being used.
+# rather than /proc/mounts.  I.e., when libmount is being used.
 df -a >out || fail=1
 grep '^rootfs' out || skip_ 'no rootfs in mtab'