Speeding up gtk-doc

[Callum McKenzie <callum physics otago ac nz>]

As everyone knows gtk-doc is horribly slow when converting docbook to
html. The problem lies partly in docbook being so painfully huge and
partly in it's poor handling of chunking. The yelp people solved this
problem by rewriting the xsl stylesheets to only support the subset of
docbook that they used. It strikes me that since gtk-doc uses an even
more restricted version of docbook (except for the template files, which
aren't restricted) it shouldn't be too difficult to write a replacement
stand-alone gtk-doc.xsl that is an order of magnitude faster than
docbook's xsl (and probably faster than yelp's). 

I have had a brief go at this problem, it isn't functional but suggests
that the order of magnitude speed-up is feasible and is worth pursuing.
I am prepared to continue with this and see what happens, but I have a
few questions :

1) What about the template code ? Handling the list Aaron suggests in
the proposed authors.html file is easy but general docbook isn't. Is it
acceptable to reject (or silently ignore) stuff that isn't understood by
my style-sheet ?

2) Is there serious interest in this ? i.e. is it desirable to sacrifice
docbook compliance for speed ? (I'm prepared to accept a "we'll see what
it looks like" answer.)

 - Callum