Issue #20624: Exception docs wording tweak - clarify that it's okay to inherit from a subclass of Exception.

Debugged by Victor.

Bug reported by Guido Vranken.

If the input stream encoding couldn't encode one or more of the
non-ascii characters in the prompt, it would fail, throwing a
UnicodeEncodeError.  Now if that happens we re-encoding using the
'replace' error handler.

Patch by Kushal Das.

Patch by Berker Peksag.

Patch by Berker Peksag.

section of the FAQ.

section of the FAQ.

Issue #21193: Make (e.g.,) pow(2, -3, 5) raise ValueError rather than TypeError.  Patch by Josh Rosenberg.