[relax-ng] Closure of infinite name-class attributes

[James Clark <jjc@jclark.com>]

> An infinite-nameclass <attribute> is required to have <text/>
> as its content.

Your example is quite convincing and this seems to me like quite a 
reasonable, intuitive restriction.  I can't think of any reason why 
somebody would need an infinite-nameclass <attribute/> with anything other 
than <text/> content.

James