[ptx] On the organization of the hugin src

[JD Smith]

I decided to take a look around the hugin CVS to get a sense of the
source and think about where I might like to contribute: what a mess (no
offense, nobody likes cleaning up)!  It seems as though the full
development process, with all its branches down many experimental or
unproductive alleys, and an early basis on other external tools (like
PanoImage) is reflected in the current directory structure, such that
it's very difficult for someone on the outside to get a "top level view"
of the relationship between the many hugin components.  Though obviously
a matter of personal taste, I suspect you might attract more developers
(like me!) if you tidy up and present a more new-developer-friendly
layout like:

hugin/        ; everything which is required to compile the hugin binary
hugin_tools/  ; external tools, like enblend, autopano, etc.
hugin_scraps/ ; old and outdated stuff, stuff hugin drew on originally

As tools are integrated directly into hugin, or their presence becomes
required, they could be moved into the hugin/ module.  

It would also help to make clear where the dependencies exist; so far I
see panoimage, jhead, vigra, nona, qt, wxwin, Panorama classes, etc.,
and of course libpano implicit in there (somewhere).  I know this is a
moving target.  I think many parts of the pano build (align, stitch,
coordinate transform, seam, etc.) process are or will soon have several
different flavors available (either actively, or as vestiges), so the
confusion is bound to grow.  

The progress on hugin and friends is very encouraging, and I think with
a bit of organization it can even accelerate!

JD