Namespaces in <exemplum>

[peterstadler]

relocating from TEIC/TEI#838

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Roma seems to be adding namespaces to <exemplum>s, e.g.
<val>20 × 30 mm</val>
becomes
<val xmlns:sch="http://purl.oclc.org/dsdl/schematron" xmlns:ns182="http://www.tei-c.org/ns/1.0">20 × 30 mm</val>

I've tried this with my own ODD and some of the templates, with the same result.