[xslt] Notification about further modification of the stylesheet-tree during compilation

["Buchcik, Kasimier" <k buchcik 4commerce de>]

Hi,

We'll extend the modification of the stylesheet tree during
compilation, in order to optimize the transformation.

In the refactored code this will include:
1) Literal result elements:
  a) Namespace aliasing will be applied on namespaces (node->ns)
     of literal result elements and their attributes.
     This means node->ns will point to a new/different struct,
     or it will be set to NULL.
     Until now, such a change of namespaces was only performed
     for cases where a node's namespace had to be converted to
     the NULL namespace.
  b) Attributes in the XSLT namespace will be _removed_

Namespace declarations (xmlNs on node->nsDef) won't be removed. 

Regards,

Kasimier