Support .St -p1003.1-2013, "IEEE Std 1003.1-2008/Cor 1-2013".

Support .St -p1003.1-2013, "IEEE Std 1003.1-2008/Cor 1-2013".

Note that the POSIX-2008 standard remains in force, so please refrain
from wholesale 2008 -> 2013 replacements.  Make sure to only use the
new -p1003.1-2013 argument for cases where "IEEE Std 1003.1(TM)-2008/
Cor 1-2013, IEEE Standard for Information Technology--Portable
Operating System Interface (POSIX(R)), Technical Corrigendum 1"
actually changes something in the standard with respect to the
specific function documented in the manual you touch.  Otherwise,
please continue using .St -p1003.1-2008.

Triggered by a similar, but slightly incorrect patch from jmc@;
ok guenther@.