Comment 39 for bug 1468027

Regarding monospace, a +1 for musashi on prepending, since I have seen SHS HW doing terrible at distinguishing 0O 1Il. If someone can verify that these chars don't look bad in Noto Mono CJK, I guess that works too.

Note that you should always only prepend half-width fonts, where ``wcwidth(foochar) == 1`` means the glyph takes exactly 1/2em, or character alignment might still go wild.