HTML entity definitions as provided by W3C.

The mapping matches the version from 10th April 2014.

The original source can be downloaded from http://www.w3.org/TR/2014/REC-xml-entity-names-20140410/.

Note: I have made one alteration, switching epsilon and varepsilon, because the meanings of these names in HTML is different from the meanings in MathML+LaTeX. See http://www.w3.org/2003/entities/2007doc/#epsilon.