Speed up document validation

[openscript]

Currently the validation of the document takes a long time:
stdin: 15202 ms (2 elems, 3 attrs, 6 spaces, 39 chars)

The reason is in the following import:

<xsd:import 
    namespace="http://www.w3.org/XML/1998/namespace"
    schemaLocation="http://www.w3.org/2001/xml.xsd"
/>

Getting the external schema is for some reason very slow and xerces doesn't cache it.

[openscript]

I've copied the schema into the project as a workaround.