Restart Node.js automatically

If you are worried about lost connections to mongolabs or node crashing, configure your apps to run in an auto restart wrapper. You have some options, one is a tool called forever, the other is production process manager (pm2) to restart node if it crashes.

Here is how to implement forever: (**note some hosting services already use forever but in some cases they don't)

These steps where tested with Linux and Windows.
1. At the command prompt type: `sudo npm install forever -g`.
2. Once it is installed type: `forever start server.js`.
3. To see if it is running type: `forever list`.

The github respository for `forever` is: https://github.com/nodejitsu/forever.

There is also a production process manager for node called `pm2`. It can also
autorestart the server, gives more control and a web interface to see the status of node applications running on the server. 

Here is how to install and use pm2:
1. Type: `sudo npm install -g pm2`.
2. Change directories into the nightscout directory: `cd pm2`.
3. Type: `pm2 start server.js` to start the server app for cgm-remote-monitor,
   for example.
4. To see if the `server.js` app is running, use the web interface which is
   running on your webserver address on port 9615), or type: `pm2 status` in
   the command line for the server.

This process manager uses the `my.env` environment variables but it keeps them even after restarting the application, so use `pm2 describe server` to view the environment variables used at the start of `server.js`.

The github repository for `pm2` is https://github.com/Unitech/PM2.