bug#24561: Unmathematical bc exponentiation behavior

[Martens, Tobias]

Hey,

echo "-(1)^2" | bc
1

I would have expected -1. This behavior is unmathematical and very confusing, 
because otherwise bc acts quite logic.
Not sure if it is mandated by POSIX, atleast I could not find it to be in the 
section of exponentiation operator. Was this ever discussed?
Resolving "-(positive float)" to "(-1)*(positive float)" for intern calculation 
seems more appropriate to me and would give the desired results.