Fix issue #17: Wrong ordering of language drop-down

I explained the source of the problem [here](https://github.com/olta/pe/issues/17#issuecomment-66934406); AFAIK, all that can be done is sort the list of languages by name before the drop-down is populated. I checked if the Be/Haiku API had some way of shwoing subdirectories in alphabetical order, but I have not come across any.
This is wrong, it won't work for languages other than English. Use `BCollator` instead.