[photran-dev] Changed non-externalized strings to warnings

[Jeffrey Overbey <overbey2@xxxxxxxxxxxx>]

In HEAD, I changed the compiler settings so that non-externalized 
strings give warnings instead of errors.

We are *required* to externalize strings as part of the release train 
(Helios this year, Indigo next year), so externalization is not 
optional.  Nevertheless, it's easier to do this after a new feature is 
"done" and its UI is stable than it is to do it along the way... giving 
compile errors was forcing us to deal with these prematurely.

Also, our numerous Bugzilla patches were all having merge problems in 
messages.properties and Messages.java, since every refactoring had to 
contribute new messages... so it might even be better to *not* 
externalize strings until the last minute, just before we commit the 
code to CVS.

Jeff