Add Language feature to UCP

Add language feature to the UCP "Unavailable Message" (at a minimum) that allows you to drop an unavailable message recorded in another language. As the system admin I currently have to create language subfolders under /var/spool/asterisk/voicemail/default/22/ for example, so for instance "en" and "fr" then have the user record their English "unavailable message" which I move into the "en" folder via the console and then have them record their French "unavailable message" which I then move into the "fr" folder.
Callers calling into the system receive the correct language through out the system including user's recorded voicemail prompts.

This is a fantastic feature of this PBX especially in multi-lingual countries and for businesses selling worldwide.