METS folks -- over here in MODS land we're trying to get version 3.0 ready
and we have an issue with xlink. The current mods version uses the mets
xlink schema, and we want to continue to use it. But we've gotten pressure
from our users to change the namespace id to the "standard" form,
i.e."http://www.w3.org/1999/xlink" rather than "http://www.w3.org/TR/xlink".
As a temporary solution I copied the mets xlink schema to the mods directory
and changed (in the mods version -- haven't touched the mets version) the
namespace id to the standard form, and