Filtering dictionaries support and unaccent dictionary

Hi there,

we'd like to introduce filtering dictionaries support for text search
and new contrib module unaccent, which provides useful example of
filtering dictionary. It finally solves the known problem of
incorrect generation of headlines of text with accents.

Also, this module provides unaccent() functions, which is a simple
wrapper on unaccent dictionary.

Regards,
Oleg

PS. I hope it's not late for July commitfest !

_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83