Remove :unicode conditionalization
While developing unicode support, we had #+unicode
and #-unicode
all over. But it seems Unicode has been available since around 2009-05. And it appears that we stopped supplying 8-bit character builds in 2012-12. There were non-unicode builds in 2012-10 but not in 2012-12.
I don't think we'll ever go back to 8-bit characters.
It's probably time to get rid of all of the conditionalization if we can.