loadkeys, locale, internationalization

The loadkeys command is a good thing but we also need a command like :
locale [country] [language]
Thus, we can set the Locale of the JNode VM and also doing a loadkeys [country] [language].

Concerning the internationalization, we should put shell messages (help on commands and their syntax) in a property file.
We display these messages for the current Locale. If the messages aren't available for the Locale, we use the english messages (always available).
This should be done early to avoid searching later for all hard coded string messages.