ttm:agent element defined as string, should be a complexType

[nigelmegitt]

The ttm:agent element is defined in metadata.xsd as xs:string, but it should be as in TTML1 §12.1.5:

<ttm:agent
  type = (person|character|group|organization|other)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute not in default or any TT namespace}>
  Content: ttm:name*, ttm:actor?
</ttm:agent>

where

<ttm:name
  type = (full|family|given|alias|other)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute not in default or any TT namespace}>
  Content: #PCDATA
</ttm:name>

and

<ttm:actor
  agent = IDREF
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute not in default or any TT namespace}>
  Content: EMPTY
</ttm:actor>