Issue #13237: Fix formatting error - the legacy shell commands weren't meant to be under the Notes heading

Issue #13237: Forward port subprocess module updates and explicitly document UTF-8 encoding assumption when universal_newlines=True

http://mail.python.org/pipermail/python-dev/2011-November/114347.html

Issue #13237: Forward port from 3.2 of subprocess documentation updates. Needed quite a few adjustments to account for new features coming in 3.3

defaulting to None like the other utimes family members. It now accepts
keyword arguments because, unlike other other functions in the family,
it has a `flags` value at the end of the argument list (which
retains its 0 default).

and lutimes.

for pointing it out.