build: Add script to update translations

README.transifex

+Updating translations
+=====================
+
+The update-transifex.sh script should be run regularly to both pull
+translations from the Transifex service, and push new strings to translate.
+
 Transifex.net Token Verification
 ================================
 

update-transifex.sh

+#!/bin/sh
+
+test -f .tx/config || exit 1
+
+echo Pulling translations from Transifex
+tx --root `dirname $0` pull --all --force --skip
+
+echo Pushing strings to Transifex
+tx push --source