[XML-SIG] Disentangling StylesheetReader from Ft.Lib

[Martin v. Loewis]

I've tried to update my 4XSLT port to use the 4Suite 0.11 code base,
only to discover that the StyleseetReader class is now much stronger
connected to Ft.Lib than before, in particular to classes from
pDomletteReader, and their specific instance attributes.

I took the approach of providing alternative base classes to the ones
provided by pDomlette, but that soon became a desaster since none of
the minidom/pulldom classes bear any relationship to how the
PyExpatReader and Handler classes work.

I'd still like pursue my attempt of integrating 4XSLT to work without
Ft.Lib, and pDomlette in particular, but I'd need some advise here.  I
feel that I miss some grand picture in all these classes, and how they
are connected. It seems that the authors of the code lose track, too,
with code duplication all over the place.

So my question is: Is all this complexity really necessary? Would it
be possible to simplify things by breaking down processing in multiple
processing steps? It seems to me that all StylesheetReader does is to
create a DOM tree, except that it creates StylesheetElement nodes
where a normal DOM build would create Element nodes. If this is really
all it does, I could propose some dramatic code reduction.

Any proposals are welcome.

Regards,
Martin