Suggested by Terry J. Reedy.

``code`` markup is enough to mark command-line fragments or to talk
about a character.  ``'c'`` is still used for actual Python string
objects.  I did a similar change in optparse.rst in r86521.

I’ve also ported two minor changes from the 3.3 version of the file
(removing an unnecessary module name in a class directive, adding a
comma).

The example version numbers were invalid and “package” was misused.  I
also made lines shorter, replaced “e-mail” with “email” (more common in
the stdlib and I believe in English generally) and tweaked a few other
things.

I made the doc for the compat alias BadZipfile shorter and used a
directive to document deprecation.

I figured there was no point of talking about zipfile.error (“the old
name” that’s older than the other old name BadZipfile) in the 3.x docs
so I just removed it.

Use startswith, instead of ==, when testing sys.platform to support
new platforms like Linux 3 or OpenBSD 5.