Separate development and production environments

Set NODE_ENV at run time or build time to switch the app between dev and
production modes.

At build time, the current NODE_ENV will be included in the packaged
app's package.json file. At runtime we read NODE_ENV from package.json,
but also allow the local environment variable to override. A query
string parsed by a preload script exposes the value to the renderer,
which then determines whether we use the staging or production server.
Additionally, different environments have different user data
directories.

// FREEBIE

js/background.js

@@ -39,6 +39,10 @@
     });
 
     var SERVER_URL = 'https://textsecure-service-staging.whispersystems.org';
+    if (window.env && window.env.node_env === 'production') {
+      SERVER_URL = 'https://textsecure-service-ca.whispersystems.org';
+    }
+
     var SERVER_PORTS = [80, 4433, 8443];
     var messageReceiver;
     window.getSocketStatus = function() {