Stop ask to re-link forever

Clear the registration flag when we detect that our credentials have
been invalidated, but retain the knowledge that we've been registered
before, so as to preserve post-first-install behaviors like skipping the
introductory install screens, and accessing the main ui.

Fix #541

// FREEBIE

js/background.js

@@ -40,9 +40,10 @@
     extension.onLaunched(function() {
         console.log('extension launched');
         storage.onready(function() {
-            if (textsecure.registration.isDone()) {
+            if (textsecure.registration.everDone()) {
                 openInbox();
-            } else {
+            }
+            if (!textsecure.registration.isDone()) {
                 extension.install();
             }
         });
@@ -180,6 +181,7 @@
         console.log(e.stack);
 
         if (e.name === 'HTTPError' && (e.code == 401 || e.code == 403)) {
+            textsecure.registration.remove();
             extension.install();
             return;
         }

js/chromium.js

@@ -165,13 +165,19 @@
     window.textsecure = window.textsecure || {};
     window.textsecure.registration = {
         done: function () {
+            storage.put("chromiumRegistrationDoneEver", "");
             storage.put("chromiumRegistrationDone", "");
             extension.trigger('registration_done');
         },
-
         isDone: function () {
             return storage.get("chromiumRegistrationDone") === "";
         },
+        everDone: function() {
+            return storage.get("chromiumRegistrationDoneEver") === "";
+        },
+        remove: function() {
+            storage.remove("chromiumRegistrationDone");
+        },
     };
 
     extension.install = function(mode) {

js/options.js

@@ -21,7 +21,7 @@
                     el: $('#install'),
                     deviceName: deviceName
                 });
-                if (bg.textsecure.registration.isDone()) {
+                if (bg.textsecure.registration.everDone()) {
                     view.selectStep(3);
                 }
                 view.$el.show();