Update docs to point to the timezone library's new home at IANA.

The recent unpleasantness with copyrights has accelerated a move that
was already in planning.

Author: tglsfdc

src/timezone/README

@@ -3,17 +3,20 @@ src/timezone/README
 Timezone
 ========
 
-This is a PostgreSQL adapted version of the timezone library from:
+This is a PostgreSQL adapted version of the timezone library from
+http://www.iana.org/time-zones
 
-	ftp://elsie.nci.nih.gov/pub/tzcode*.tar.gz
+The source code can be found at:
+
+	ftp://ftp.iana.org/tz/releases/tzcode*.tar.gz
 
 The code is currently synced with release 2010c.  There are many cosmetic
 (and not so cosmetic) differences from the original tzcode library, but
 diffs in the upstream version should usually be propagated to our version.
 
 The data files under data/ are an exact copy of the latest data set from:
 
-	ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz
+	ftp://ftp.iana.org/tz/releases/tzdata*.tar.gz
 
 Since time zone rules change frequently in some parts of the world,
 we should endeavor to update the data files before each PostgreSQL