#21347: use string not list in shell=True example.

Patch by Akira.
Issue #21488: Fix doc of codecs.decode() and codecs.encode(), no keyword support.
Patch written by Brad Aylsworth.
Issue #21488: Add support of keyword arguments for codecs.encode and codecs.decode
Backed out changeset 6ceedbd88b5f
Issue #21497: faulthandler functions now raise a better error if sys.stderr is
None: RuntimeError("sys.stderr is None") instead of AttributeError("'NoneType'
object has no attribute 'fileno'").
Issue #21075: fileinput.FileInput now reads bytes from standard stream if
binary mode is specified.  Patch by Sam Kimbrel.
Issue #20998: Fixed re.fullmatch() of repeated single character pattern
with ignore case.  Original patch by Matthew Barnett.
Issue #21488: Oops, the patch for codecs.encode/decode doc was written by
Berker Peksag (already present in Misc/ACKS). The issue was reported by Brad
Aylsworth.