[Suggestion] In MathML conversion, add mathvariant="normal" for \text{...}

Currently, \text{...} is displayed as a single identifier (<mi>...</mi>). In some rendering engines (such as the one used by Eclipse), all identifiers are displayed in italics.

I think it would be beneficial to display \text{...} as <mi mathvariant="normal">...</mi>, which will ensure that the text is displayed in a normal font (some rendering engines, such as the one used by Firefox, do this automatically for multi-character identifiers, but I do not believe that this is in the spec).