Re: couple of warning fixes

[Akim Demaille]

|  Akim> Actually, I'm frightened: how come Perl does not complain about
|  Akim> $languages{''}?  It is not supposed to exist.  Does it?
| 
| I beleive it's undefined too but that it was not used in places
| where a defined value is needed.  Who knows? After all, that's Perl.

Hm, so you are saying $my_hash{undef} triggers a warning, but not
$my_hash{some_undefined_key}, right?  It makes sense.  Hm, worse yet,
AFAIR, the latter *defines* the corresponding entry in the hash, but
maps it to undef.  Bleah.

| Maybe it could be cleaner to register an `unknown' language?

I fail to see what use we could make of it?