Beta versions support: SxS support, in-app env/instance display (#1606)

* Script for beta config; unique data dir, in-app env/type display

To release a beta build, increment the version and add -beta-N to the
end, then go through all the standard release activities.

The prepare-build npm script then updates key bits of the package.json
to ensure that the beta build can be installed alongside a production
build. This includes a new name ('Signal Beta') and a different location
for application data.

Note: Beta builds can be installed alongside production builds.

As part of this, a couple new bits of data are shown across the app:

- Environment (development or test, not shown if production)
- App Instance (disabled in production; used for multiple accounts)

These are shown in:

- The window title - both environment and app instance. You can tell
  beta builds because the app name, preceding these data bits, is
  different.
- The about window - both environment and app instance. You can tell
  beta builds from the version number.
- The header added to the debug log - just environment. The version
  number will tell us if it's a beta build, and app instance isn't
  helpful.

* Turn on single-window mode in non-production modes

Because it's really frightening when you see 'unable to read from db'
errors in the console.

* aply.sh: More instructions for initial setup and testing

* Gruntfile: Get consistent with use of package.json datas

* Linux: manually update desktop keys, since macros not available

main.js

@@ -3,7 +3,7 @@ const url = require('url');
 const os = require('os');
 
 const _ = require('lodash');
-const electron = require('electron')
+const electron = require('electron');
 
 const BrowserWindow = electron.BrowserWindow;
 const app = electron.app;
@@ -11,20 +11,26 @@ const ipc = electron.ipcMain;
 const Menu = electron.Menu;
 const shell = electron.shell;
 
+const packageJson = require('./package.json');
 const autoUpdate = require('./app/auto_update');
 const windowState = require('./app/window_state');
 
 
-console.log('setting AUMID');
-app.setAppUserModelId('org.whispersystems.signal-desktop')
+const aumid = 'org.whispersystems.' + packageJson.name;
+console.log('setting AUMID to ' + aumid);
+app.setAppUserModelId(aumid);
 
 // Keep a global reference of the window object, if you don't, the window will
-// be closed automatically when the JavaScript object is garbage collected.
+//   be closed automatically when the JavaScript object is garbage collected.
 let mainWindow;
 
 const config = require("./app/config");
 
-if (config.environment === 'production' && !process.mas) {
+// Very important to put before the single instance check, since it is based on the
+//   userData directory.
+const userConfig = require('./app/user_config');
+
+if (!process.mas) {
   console.log('making app single instance');
   var shouldQuit = app.makeSingleInstance(function(commandLine, workingDirectory) {
     // Someone tried to run a second instance, we should focus our window
@@ -36,16 +42,15 @@ if (config.environment === 'production' && !process.mas) {
   });
 
   if (shouldQuit) {
-    console.log('quitting');
+    console.log('quitting; we are the second instance');
     app.quit();
     return;
   }
 }
 
-const userConfig = require('./app/user_config');
 const logging = require('./app/logging');
 
-// this must be after we set up appPath in user_config.js
+// This must be after we set up appPath in user_config.js, so we know where logs go
 logging.initialize();
 const logger = logging.getLogger();
 
@@ -60,6 +65,7 @@ function prepareURL(pathSegments) {
     protocol: 'file:',
     slashes: true,
     query: {
+      name: packageJson.productName,
       locale: locale.name,
       version: app.getVersion(),
       buildExpiration: config.get('buildExpiration'),
@@ -69,6 +75,7 @@ function prepareURL(pathSegments) {
       environment: config.environment,
       node_version: process.versions.node,
       hostname: os.hostname(),
+      appInstance: process.env.NODE_APP_INSTANCE,
     }
   })
 }