Julia: Manual line wrapping of exceptions looks bad on narrow terminal

[TotalVerb]

This is a rather minor point, but I think showerror exceptions would look better if the terminal emulator were allowed to wrap them instead of being manually line-wrapped. This is especially the case on narrow terminals:

I think it might be better just to print all the explanatory text on one line. Thoughts?

[simonster]

If you print it as a single line the terminal will break it in the middle of words, so that won't look very good either, but it may make sense to re-wrap to the column width specified by tty_size().

[StefanKarpinski]

Might make sense to hook into the mimetype system more thoroughly.