Added waitUntilVisibleAfterRefresh and textsToWaitFor - both discussed with @witzig.

Page objects refactored to exploit textsToWaitFor if relevant.

Login tests refactored for the newer API.

Some additional tests in subscription. The rest at least included as "pending".

test/e2e/lib/mail.js

@@ -0,0 +1,19 @@
+'use strict';
+
+const config = require('./config');
+const driver = require('./mocha-e2e').driver;
+const page = require('./page');
+
+module.exports = (...extras) => page({
+
+    async fetchMail(address) {
+        await driver.sleep(1000);
+        await driver.navigate().to(`${config.mailUrl}/${address}`);
+        await this.waitUntilVisible();
+    },
+
+    async ensureUrl(path) {
+        throw new Error('Unsupported method.');
+    },
+
+}, ...extras);