Add comment for posixly_correct.
tree0fe4401d824921ec97df38afd343873e1961d2f2
-rw-r--r-- 11339 ABOUT-NLS
-rw-r--r-- 17996 COPYING
-rw-r--r-- 7831 INSTALL
-rw-r--r-- 1114 THANKS
drwxr-xr-x - doc
drwxr-xr-x - lib
drwxr-xr-x - m4
drwxr-xr-x - old
drwxr-xr-x - po
drwxr-xr-x - src
drwxr-xr-x - tests