xmlns talisman on HTML fragments in SVG/MathML

SVG can contain HTML fragments in foreignObject, e.g. iframe. MathML can  
also contain HTML, e.g. form controls.

In order to have source-level consistency between text/html and XML, the  
xmlns talisman should be allowed on any HTML element that has an SVG or  
MathML namespaced parent.

-- 
Simon Pieters
Opera Software