python3-docutils: Upgrade to 0.17.1

python3-docutils: Upgrade to 0.17.1

This was in meta-python for a while so merge the changes here
and  upgrade, once applied, delete from meta-python

License-Change: Deleted legacy stylesheets from LICENSE [1]
                Updated URI for BSD-2 [2]

[1] https://sourceforge.net/p/docutils/code/8487/
[2] https://sourceforge.net/p/docutils/code/8554/

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>