#4686 display properties for transpose

[Robert Dodier]

I notice that transpose doesn't have a pretty printer 2d display property. I am inclined to display it as a superscript T. I wonder if that should apply only to the noun form -- maybe, maybe not.

Likewise it looks like there isn't a TeX function for transpose.

For good measure I guess we probably want to make any MathML output (I think there are a two packages, I could be mistaken) consistent with the pretty printer and TeX output.