several improvements to DO overlay

- Use promises to prevent race conditions.
- Introduce a new `shouldHijackDO` global setting, which DO content script
  checks before proceeding. We can toggle that to false whenever we should no
  longer hijack DigitalOcean, e.g. once the user has completed cloud setup.
- Actually check the `activePromoId` global setting to determine whether to
  include the promo code text input in our overlay. Previously we were always
  including it.
- Enable i18n in the overlay.

src/chrome/extension/scripts/background.ts

@@ -36,19 +36,31 @@ chrome.runtime.onSuspend.addListener(() => {
 });
 
 chrome.runtime.onMessage.addListener((request :any, sender: chrome.runtime.MessageSender, sendResponse :Function) => {
+  if (!request) return;
+
   // handle requests from other pages (i.e. copypaste.html) to bring the
   // chrome popup to the front
-  if (request && request.openWindow) {
+  if (request.openWindow) {
     browserApi.bringUproxyToFront();
   }
 
   // handle requests to get logs
-  if (request && request.getLogs) {
+  if (request.getLogs) {
     core.getLogs().then((logs) => {
       sendResponse({ logs: logs });
     });
     return true;
   }
+
+  if (request.globalSettingsRequest) {
+    browserApi.emit('globalSettingsRequest', sendResponse);
+    return true;
+  }
+
+  if (request.translations) {
+    browserApi.emit('translationsRequest', request.translations, sendResponse);
+    return true;
+  }
 });
 
 chrome.runtime.onMessageExternal.addListener((request :any, sender :chrome.runtime.MessageSender, sendResponse :Function) => {

src/generic_core/globals.ts

@@ -57,6 +57,7 @@ export var settings :uproxy_core_api.GlobalSettings = {
   enforceProxyServerValidity: false,
   validProxyServers: [],
   activePromoId: null,  // set on promoIdDetected
+  shouldHijackDO: true,
   crypto: true
 };
 

src/generic_ui/locales/en/messages.json

@@ -1422,5 +1422,26 @@
   "HAVE_PROMO_CODE": {
     "description": "Label for a checkbox indicating that you have a promo code",
     "message": "I have a promo code"
+  },
+  "AUTHORIZE_DIGITALOCEAN": {
+    "message": "Authorize uProxy to connect with DigitalOcean"
+  },
+  "PROCEED_TO_UPROXY": {
+    "message": "Proceed to uProxy"
+  },
+  "ENTER_PROMO": {
+    "message": "Have a promo code? Enter it here."
+  },
+  "PROMO_ACCEPTED": {
+    "message": "Promo code accepted!"
+  },
+  "PROMO_FAILED": {
+    "message": "Could not apply promo code."
+  },
+  "PROCESSING": {
+    "message": "processing..."
+  },
+  "APPLY": {
+    "message": "Apply"
   }
 }