Add geolite-legacy 2015-03-26

The geoip package only installs a GeoIP _library_ which is useless
without a GeoIP _database_.

The only package to currently install such a database is ntopng, which
manually downloads Maxmind's GeoLite Legacy files to a private location.

Provide these as a separate package so other packages can use them as
well.

pkgs/data/misc/geolite-legacy/builder.sh

@@ -0,0 +1,19 @@
+#!/bin/sh -e
+
+source "$stdenv/setup"
+
+mkdir -p $out/share/GeoIP
+cd $out/share/GeoIP
+
+# Iterate over all environment variable names beginning with "src":
+for var in "${!src@}"; do
+	# Store the value of the variable with name $var in $src:
+	eval src="\$$var"
+
+	# Copy $src to current directory, removing Nix hash from the filename:
+	dest="${src##*/}"
+	dest="${dest#*-}"
+	cp "$src" "$dest"
+done
+
+gunzip -v *.gz