Update of Library Project to solve Nexus problems

I've tested this on my Nexus 7 and scanning works and so solves Issue #4.

The code was pulled from ```phonegap-plugins\Android\BarcodeScanner\2.2.0\LibraryProject``` and built with PG 2.9.0 and Android SDK 17.

Note that standard size barcodes are not working on Nexus 7 but this is due to low resolution of the camera.