list/e splits arg list using prime factorization of length

Possible performance benefits
use available library function

Missed this earlier
Fix prime-splitting list/e bug
list/e performance tweak
refactor graph-data to make it easier to use externally
unbreak redex pdf docs build

please include in the release
extraneous "false"
Update TR history.

Please merge to 6.1.1.
name variable consistently
note v6.1.1 in Racket "HISTORY.txt"

Merge to v6.1.1