[Uim] m17nlib working after all

[David Oftedal]

Oh, sorry, I found m17nlib in Gentoo Portage after all. And it seems 
that it's autodetected even with the Gentoo sandbox feature turned on. 
So it wasn't at all as hard as I thought!

Obviously methods like pinyin don't work too well without the preedit, 
but otherwise it's working great! I'll find whoever was looking for an 
Arabic input method and tell him about it.

-David