Missing SVG tags and attributes

Problem

Note from maintainers: Starting with React 15, we should have a complete support of the subset of SVG specifications that is actually implemented by browsers. If you find a missing attribute, or if a tag does not work correctly, please write a comment below. Note that `React.DOM.*` factory functions might not provide all tags, but you should be able to use `React.createFactory` or `React.createElement()` directly for the missing ones. Or you can just use JSX which translates to `React.createElement()` and supports all tags inherently.