Namespace, or not

[bdarcus]

Premature, but if this goes anywhere ...

Namespace

If in doubt, just add it.

• It may be overkill, since we have no need to mix with nodes of other schemas
• but that could provide another avenue for extension with attributes (could allow foreign-namespaced attributes in places)
• also, ensures clear distinction from CSL 1 (this would have a different namespace probably)
• see below

Another big question: should attributes be namespaced? I guess currently they're not.