[xmlsec] using SAX with xmlsec

[Aleksey Sanin]

The xmlsec currently requires building the whole DOM tree. I think it is 
possible
to write XML DSig implementation on top of SAX for *some* very restricted
set of signatures (for example, you have to limit allowed XPath transforms,
<dsig:Signature/> element should go first, etc.). But this is a 
completely different
story.

Aleksey