Refactor the urllib open_http() and open_https() to use the same
internal logic.  The only difference between the two is the call to
constructor an HTTPConnection object.

Change various socket APIs to use bytes or str instead str8.

The two clients in the std library have been updated to use the newer
interface.  A couple of minor changes to the httplib tests were
needed.

Also, reformat some long lines in the httplib tests.

Note that it's hard to test xmlrpclib, because the server it attempts
to connect to doesn't seem to support the expected interfaces.  Many
of the links via xmlrpc.com are dead, so I couldn't find another
server to use for tests.

Even if it isn't, it shouldn't be changed based on the locale setting IMO.
(Incidentally, this makes test_csv.py pass again on my box.)

 - fix "h[sbseek] == b'\1'" and "ratecode = ord(h[sbseek+4])" in test_voc()
 - avoid division by zero
 - use startswith method: replace h[:2] == b'BM' by h.startswith(b'BM')
 - use aifc.open() instead of old aifc.openfp()
 - use ord(b'P') instead of ord('P')

in utf-8.

Use bit fields for flags to reduce memory usage.
Return booleans where they are documented.  Although a boolean for
seekable seems a bit odd when it can be unknown.  Add a comment about this.

modules have unittests AFAICT, and I'm not improving things here, but these
changes make a bunch of email package tests succeed, and command line testing
against real files seems to make things better.

Added an __main__ section to imghdr.py so that it can be run from the command
line similarly to sndhdr.py.  Someone else can figure out a better -m way of
doing this.

In sndhdr.py do a couple of very minor cleanups, and use a with statement to
not wait for gc to close the file.