ResourceBundle.getBundle(): zh_TW locale should fallback to "en" locale

ResourceBundle::getBundle() method should fallback back to "en" locale if "zh_TW" locale
resources are not found.

Currently in JDK-1.4.1, in the absense of "zh_TW" resources, it fall backs to "zh" resources.
Instead it should fallback to "en" resources. This would be an exception to the default
resource bundle resolution machanism. Though, i'm not sure whether this is a valid requirement
on JDK side.
###@###.### 2004-05-18