Update for latest Xcode
Ported from ZXing: "Issue 1295 allow broader definition of  URI"
Ported from ZXing: "Add some necessary test changes. Some strange
strings are now recognized as URL-like but it isn't a problem. Don't
lowercase URI schemes."
Ported from ZXing: "Forgot one more test change"
Ported from ZXing: "One final simplification"
Set deployment targets to iOS 4.3 and OS X 10.7