Spec says:
ExpandedName ::= '{' Namespace '}' LocalName
where
Namespace ::= EmptyString | Uri
So "{}foo" is an expanded form with empty ns uri but also is a local name,
cause "{" and "}" are valid chars NT-chars (
http://www.w3.org/TR/xml/#NT-Char)
And there is still a question how would Jackrabbit 2.0 recognize path like
/{}foo/ ? ;)
