de/lingo-dic.txt: Merge & uniq.
de/lingo-mul.txt: Uniq.
de/lingo-syn.txt: Uniq.
en/lingo-wdn.txt: Merge & uniq.
en/lingo-mul.txt: Uniq.
en/lingo-dic.txt: Merge & uniq.
{de,en,ru}/: Unified headers.