with debuglevel=1 only the header keys got printed. With
this change the header values get printed as well and the single
header entries get '\n' as a separator.

bpo-31399: Let OpenSSL verify hostname and IP

The ssl module now uses OpenSSL's X509_VERIFY_PARAM_set1_host() and
X509_VERIFY_PARAM_set1_ip() API to verify hostname and IP addresses.

* Remove match_hostname calls
* Check for libssl with set1_host, libssl must provide X509_VERIFY_PARAM_set1_host()
* Add documentation for OpenSSL 1.0.2 requirement
* Don't support OpenSSL special mode with a leading dot, e.g. ".example.org" matches "www.example.org". It's not standard conform.
* Add hostname_checks_common_name

Signed-off-by: Christian Heimes <christian@python.org>

* Fix multiple typos in code comments

* Add spacing in comments (test_logging.py, test_math.py)

* Fix spaces at the beginning of comments in test_logging.py

blocksize was hardcoded to 8192, preventing efficient upload when using
file-like body. Add blocksize argument to __init__, so users can
configure the blocksize to fit their needs.

I tested this uploading data from /dev/zero to a web server dropping the
received data, to test the overhead of the HTTPConnection.send() with a
file-like object.

Here is an example 10g upload with the default buffer size (8192):

$ time ~/src/cpython/release/python upload-httplib.py 10 https://localhost:8000/
Uploaded 10.00g in 17.53 seconds (584.00m/s)

real	0m17.574s
user	0m8.887s
sys	0m5.971s

Same with 512k blocksize:

$ time ~/src/cpython/release/python upload-httplib.py 10 https://localhost:8000/
Uploaded 10.00g in 6.60 seconds (1551.15m/s)

real	0m6.641s
user	0m3.426s
sys	0m2.162s

In real world usage the difference will be smaller, depending on the
local and remote storage and the network.

See https://github.com/nirs/http-bench for more info.

The deprecation include manual creation of SSLSocket and certfile/keyfile
(or similar) in ftplib, httplib, imaplib, smtplib, poplib and urllib.

ssl.wrap_socket() is not marked as deprecated yet.