Add getByLocale() and toLocale() to ScriptCode

[dwalluck]

Add getByLocale(Locale) and toLocale() to ScriptCode. These methods already exist in CountryCode, LanguageCode, and LocaleCode.

Calling toLocale() always returns a Locale with the just the script set.

Script support wasn't added to Locale until Java 1.7, so calling either method will increase the minimum Java version required at runtime from Java 1.5 to Java 1.7.