digiKam from trunk: first import of Haar algorithm to perform fuzzy search around whole collection of image.

Marcel, the code have been extracted from imageseek program (<a href="http://www.imgseek.net">http://www.imgseek.net</a>;) several methods can be removed and optimized here, especially in imgdb.cpp do not look how is computed haar matrix, just look the result provided to store values in DB and to compare both matrix when we will perform search.

It's not very complicated (:=)))

The code need to be interfaced to digiKam DB backend.
We need to talking about this code by IRC or mail...