
This function can be called inside a VSP page to apply an XSLT
stylesheet to the output of the page once the page is complete.  This
function will return immediately and the stylesheet will not be
applied until the page is successfully formed.  Any errors arising in
the stylesheet processing will be reported to the web client.

The stylesheet does not have to be previously defined.  The URI
supplied will be used to locate the stylesheet.  This can be a file,
an HTTP URL or a virt:// URI for a stylesheet stored in a local table.
Virtuoso will cache the stylesheet after first use.  You can clear the
cache entry with the xslt_stale() function.

For this to work the text generated by the VSP page should be well-formed XML.

This function is only valid in a VSP context.  The
xsl:output element will control the
Content-Type sent to the user agent.
