maint: change all references: s/POSIX\.2/POSIX/

There is no longer any point in referring to POSIX.N.
POSIX is sufficient.
* doc/grep.in.1: As above.
* src/main.c (main): Likewise.
* tests/file: Likewise.
* tests/options: Likewise.
* ChangeLog: Likewise.
* NEWS: Likewise.
* cfg.mk: Update, to match changed NEWS.
Inspired by Glenn Golden's suggestion in http://bugs.gnu.org/15486

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/file b/tests/file
index 8cdfc8de..33142442 100755
--- a/tests/file
+++ b/tests/file
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Test for POSIX.2 options for grep:
+# Test for POSIX options for grep:
 # grep -E -f pattern_file file
 # grep -F -f pattern_file file
 # grep -G -f pattern_file file