Made barcode generator work for iOS 5/6
Fixed typo from last commit
Added AVMetadataObjectTypeFace constant, to avoid 'dyld: Symbol not found:' error when running on iOS 5
Disabled antialias in barcode generator, so the generated image looks better on non-retina displays
Creation of QR, PDF417 and Aztec codes is only available in iOS 6 and above
Merge pull request #8 from MacMannes/master

Made barcode generator work for iOS 5/6