pgsql: Remove comment on errno=0 lines, but add mention to port/strtol.c

Log Message:
-----------
Remove comment on errno=0 lines, but add mention to port/strtol.c function.

Modified Files:
--------------
pgsql/src/backend/utils/adt:
datetime.c (r1.164 -> r1.165)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/datetime.c.diff?r1=1.164&r2=1.165)
float.c (r1.118 -> r1.119)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/float.c.diff?r1=1.118&r2=1.119)
numutils.c (r1.71 -> r1.72)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/numutils.c.diff?r1=1.71&r2=1.72)
pgsql/src/port:
strtol.c (r1.8 -> r1.9)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/strtol.c.diff?r1=1.8&r2=1.9)