
This function can be used to force Virtuoso to reload a cached
stylesheet from the URI when next used with
xslt() or http_xslt().
Using this function before every application of the stylesheet is
extremely inefficient.  If stylesheets are stored in the database, you
can use this function in an update trigger on the table storing the
stylesheets but you should not use it before every application of the
sheet.
This function never needs to be applied to a stylesheet URI with
the file protocol since xslt() and
http_xslt() will automatically detect a stale
cache entry.  However if the stylesheet is stored on a remote web
server, this function is needed to force a reload.
