Ok, unit text works in a weird way.  Cleaning.

I have to initialize the sf::Text when I create it, which is tough
in a class.  Maybe I can just pass it the empty string and work in
the rest later.
Unit text works properly within the class!

The problem, I'm pretty sure, was that the font gets stored by ptr
but that disappears after the function returns that called it.
Solution: pass in font to set_info by reference, then dereference
when doing info_str.setFont()
Unit strength displays update after battle.