- note early on that the result of struct.pack includes padding
   bytes by default

 - add examples showing how order of struct fields can affect size
   (due to padding)

 - better headers and references; introduction to format strings

 - integrate packing notes into table

Many thanks to Meador Inge for the patch.

Instead of spaces between the filename and date (or whatever the string
is that follows the filename, if any) use tabs.  This is what the unix
'diff' command does, for example, and difflib was intended to follow
the 'standard' way of doing diffs.  This improves compatibility with
patch tools.  The docs and examples are also changed to recommended that
the date format used be the ISO 8601 format, which is what modern diff
tools emit by default.

Patch by Anatoly Techtonik.

Fixed a typo in the email.encoders module so that messages output using
an ISO-2022 character set will use a content-transfer-encoding of
7bit consistently.  Previously if the input data had any eight bit
characters the output data would get marked as 8bit even though it
was actually 7bit.

When such extra options include "-x testname", subsequent arguments
are all taken as test names to ignore. Therefore, standard options
must be passed before *TESTOPTS.

(witnessed on the ARM buildbots)

to cover recent locale changes and additions.

1. The assumptions in check_node() were too restrictive:

     - Hardware addresses with universal_local_bit=1 are valid
       (locally administered).

     - Many of the tested functions (including uuid.getnode())
       may return valid RFC 4122 random node IDs. These are pretty
       much random 48-bit values with the multicast bit set to 1.

2. _unixdll_getnode() calls _uuid_generate_time(), which may be None
   on some platforms. The resulting TypeError is now caught.

its tests

The test_classify_oldstyle and test_classify_newstyle methods of
test.test_inspect.TestClassesAndFunctions were previously almost
identical (aside from irrelevant whitespace and one semantic
difference).  They now share a single helper.

Fixes issue #8363.

Try to turn some buildbots green by allowing test_multiprocessing to pass even if it hits the sys.exc_clear code in the threading module, and improve the test coverage by making the ctypes dependencies a bit more granular (two of the cited ctypes objects don't exist on my system)