GraphicsMagick code landed in default/HEAD branch

Hi,

I just committed the GraphicsMagick patchset to default branch.

As result, transcode no longer depends on ImageMagick, but on
GraphicsMagick (http://www.graphicsmagick.org) instead.

As reminder, the basic rationale for this move was the need for a
stabler (and saner? ) API/ABI.

Unfortunately I got some networking annoyances that prevented me to
push the changes on berlios' tcforge.

I've taken the chance to rewrite heavily all the involved modules,
including a deep refactoring of filters.
The port also showed up a few libtcext glitches which I'm resolving 
as soon as they pop up[1].

Until the affected modules get a new round of testing, expect strange
behaviours from them.

The full list of affected modules follows.

import/import_im
import/import_imlist (already deprecated)
encode/encode_im (should be reasonnably safe)
filter/filter_logo (deeply rewritten)
filter/filter_logoaway (ditto)
filter/filter_compare (ditto)


+++

[1] In the middle/long term, we should eventually find out a smarter
linking strategy.

Bests,

-- 
Francesco Romani // Ikitt
http://fromani.exit1.org  ::: transcode homepage
http://tcforge.berlios.de ::: transcode experimental forge