CR 1.9 allow any attribute from other namespaces on METS elements

If I recall correctly, there was some reason not do to this on the elements where we already have xlink:.

But the basic idea is that on as many elements as practical, or maybe a restricted set of elements, allow any attribute as long as it is in an xmlns.

<div xmlns:ext="httpx://example.com/my-extension" ext:fred="gravy" TYPE="image">

if there is an xsiSchemaLocation for httpx://example.com/my-extension it should get validated against it.

(httpx is to prevent auto linking in the example)

---

Note added by Rick Beaubien

It appears to me that we would need to add the following element to the elements that declare the attributes for each element on which we wish to support anyAttribute:

<xsd:anyAttribute namespace="##other" processContents="lax"/>

Offhand, I can't see why anyAttribute shouldn't be supported on elements which also include xlink defined attributes.