* There are only two base-64 alphabets defined by the RFCs, not three
* Due to the internal translation, plus (+) and slash (/) are never discarded
* standard_ and urlsafe_b64decode() discard characters as well
* Make it more obvious gettarinfo() is based on stat(), and that non-ordinary
files may need special care
* Filename taken from fileobj.name; suggest dummy arcname as a workaround
* Indicate TarInfo may be used directly, not just via gettarinfo()
* Add headings for each concrete and mix-in class and list methods and
attributes under them
* Fix class and method cross references
* Changed RequestHandler to BaseRequestHandler and added class heading
* Pull out Stream/DatagramRequestHandler definitions
* Reordered the request handler setup(), handle(), finish() methods
* Document constructor parameters for the server classes
* There was a link pointing to the section on the string.Formatter class (and
multiple links in Python 3), when the section on the common format string
syntax is probably more appropriate
* Fix references to various format() functions and methods
* Nested replacement fields may contain conversions and format specifiers,
and this is tested in Python 3; see Issue #19729 for instance
