Support for negative qr

[LPFinch]

Thanks for view. I added support for negative(white code on black bg) QR scanning in my app in automatic mode. It would be nice if you join this shit to the library(manual and auto mode). Easy solution to negate row and matrix

BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(new PlanarRotatedYUVLuminanceSource(image, width, height, 0, 0, width, height, true).invert()));

Regards

[livotov]

cool! will add this under a configuration option