lib/time: update time zone to IANA version 2013b

Update #4553.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/8293043

lib/time/update.bash

@@ -7,8 +7,8 @@
 # downloaded from the ICANN/IANA distribution.
 
 # Versions to use.
-CODE=2011i
-DATA=2011n
+CODE=2013b
+DATA=2013b
 
 set -e
 rm -rf work