ISSUE-116: D3C: setting Node.prefix on non-namespaced node types

ISSUE-116: D3C: setting Node.prefix on non-namespaced node types

http://www.w3.org/2005/06/tracker/webapi/issues/116

Raised by: Bjoern Hoehrmann
On product: DOM 3 Core

The current DOM Level 3 Core specification is unclear how to handle 
setting Node.prefix for node types that do not have a concept of 
namespaces like text nodes. Like in ISSUE-115 it says both that doing 
so has no effect and that it would result in a NAMESPACE_ERR. For 
additional complexity, what if the node is read-only?