title: barcodescanner phonegap plugin issue
body: <p>I'm currently trying to implement barcodescanner in my phonegap project.
  But I'm completly lost because I read a lot of topics about barecodescanner and all possible solutions provided didn't work for me.</p>
  
  <p>First, some tutorials and documents says that I have to use
  cordova.plugin.barcodeScanner.scan (...). But for me, cordova.plugin is always undefined.</p>
  
  <p>Some others says that I have to do cordova.require("cordova/plugin/BarcodeScanner"); and it doesn't work, when I run my app, I get the following error : "module "cordova/plugin/BarcodeScanner" not found.</p>