packed trie for hyphenation patterns in the main repository

Hi,

I just pushed the packed trie implementation from
http://flpsed.org/hgweb/dillo_hyphen_mem to the main repository.
It considerably reduces the memory consumption of the hyphenator.
The <lang>.pat files of the original implementation without
any changes.
However one can reduce memory consumption even further by
precompressing the patterns using the new test/trie program:

Usage:
trie <pattern file> > <prefix>/lib/dillo/hyphenation/<lang>.pat.trie
    
e.g:
./trie hyph-de-1996.pat > /usr/local/lib/dillo/hyphenation/de.pat.trie
    
If the <lang>.pat.trie is found, dillo will use this precompressed trie
instead of the <lang>.pat file.

These changes should not have any effect on where the hyphenator
breaks up words. If you find any regressions or changes, please
report them.

Cheers,
Johannes