New way of adding internationalized messages. This affects the Derby Reference Guide.

[Rick Hillegas]

My last checkin (469975, DERBY-1868) changed the way that we add 
internationalized messages to the Derby engine. There is now a file of 
xml descriptors (java/engine/org/apache/derby/loc/messages.xml). This is 
where we should add new engine messages. As part of adding a new 
message, you will want to give friendly names to the message 
arguments--these friendly names will appear in the SQLState tables in 
the Derby Reference Guide.

Please do not edit java/engine/apache/derby/loc/messages.xml. This file 
has been removed from code management and is now generated from 
messages.xml during the Derby build.

Thanks,
-Rick