Support loading of dictionary from custom data stream

[annulen]

hnj_hyphen_load expects file name which could be passed to fopen(), however I'd like to load dictionaries from Qt resources [1]. In this case there is no actual file on disk, but it could be read into memory with Qt API. I can see the next possible solutions:

1. Add public function accepting callback for reading lines
2. Add public function loading character buffer containing whole dictionary

I think (1) is easier to implement, while (2) may be considered simpler API.

Would such feature be welcome in libhyphen?

[1] Background: I'm working on QtWebKit, libhyphen is used for CSS hyphens, and I'd like to simplify redistribution of library on platforms like Windows where installing dictionaries system-wide dictionaries is not an option