Also made the smtplib markup consistent with the rest of the markup.

Fixed reference leak in error branch of _bufferedreader_read_all(). The variable data can contain a bytes object but it wasn't cleaned up when PyList_New() failed. CID 715364

Also minor formatting cleanups.

Fixed out-of-bounce write to rawmode buffer. The fixed size buffer wasn't enlarged for the new 'x' flag. The buffer may contain the 5 flags xrwa+ and the \0 byte

Closes #15925: fix regression in parsedate() and parsedate_tz() that should return None if unable to parse the argument.

Issue #15977: Fix memory leak in Modules/_ssl.c when the function _set_npn_protocols() is called multiple times

constructing infinities. This is done for backwards compatibility
with decimal.py: Infinity coefficients are undefined in _decimal
(in accordance with the specification).