Adding scratch-l10n dependency

* Added .tx configuation to be able to send source strings to transifex
* added dependency on scratch-l10n 2.x, and removed everything related to generating the l10n messages locally
* updated playground intl reducer to use paint messages from l10n package

scripts/generate-locale-messages.js

@@ -1,67 +0,0 @@
-#!/usr/bin/env node
-
-/*
-Generates locale/messages.json from current translastion files
-
-Translations are expected to be in the ./translations directory.
-Translation files are in Chrome i18n json format:
-'''
-{
-    "message.id": {
-        "message": "The translated text",
-        "description": "Tips for translators"
-    },
-    ...
-}
-'''
-They are named by locale, for example: 'fr.json' or 'zh-cn.json'
-
-Current languages supported are listed in ../src/languages.json
-
-Converts the collection of translation files to a single set of messages.
-Example output:
-'''
-{
-  "en": {
-    "action.addBackdrop": "Add Backdrop",
-    "action.addCostume": "Add Costume",
-    "action.recordSound": "Record Sound",
-    "action.addSound": "Add Sound"
-  },
-  "fr": {
-    "action.addSound": "Ajouter Son",
-    "action.addCostume": "Ajouter Costume",
-    "action.addBackdrop": "Ajouter Arrière-plan",
-    "action.recordSound": "Enregistrement du Son"
-  }
-}
-'''
-
-Missing locales are ignored, react-intl will use the default messages for them.
- */
-const fs = require('fs');
-const path = require('path');
-const mkdirp = require('mkdirp');
-
-const locales = ['en'];
-const LANG_DIR = './translations/';
-const MSGS_DIR = './locale/';
-
-let messages = locales.reduce((collection, lang) => {
-    let langMessages = {};
-    try {
-        let langData = JSON.parse(
-            fs.readFileSync(path.resolve(LANG_DIR, lang + '.json'), 'utf8')
-        );
-        Object.keys(langData).forEach((id) => {
-            langMessages[id] = langData[id].message;
-        });
-        collection[lang] = langMessages;
-    } catch (e) {
-        process.stdout.write(lang + ' translation file missing, will use defaults.\n');
-    }
-    return collection;
-}, {});
-
-mkdirp.sync(MSGS_DIR);
-fs.writeFileSync(MSGS_DIR + 'messages.json', JSON.stringify(messages, null, 2));