Add full support for SVG 1.1

Adds all the missing elements from http://www.w3.org/TR/SVG/eltindex.html
Adds all the missing attributes, except for the event related ones (starting with 'on') from http://www.w3.org/TR/SVG/attindex.html

Updates documentation.

Adds support for namespaced attributes that need `setAttributeNS`

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