_PyTime_Divide() rounding was wrong: copy code from Python default which has
now much better unit tests.

Oops, I forgot to document my change.

PyObject_Length() returns a P_ssize_t, not an int. Use a Py_ssize_t to avoid
overflow.

On Windows, the tv_sec field of the timeval structure has the type C long,
whereas it has the type C time_t on all other platforms. A C long has a size of
32 bits (signed inter, 1 bit for the sign, 31 bits for the value) which is not
enough to store an Epoch timestamp after the year 2038.

Add the _PyTime_AsTimevalTime_t() function written for datetime.datetime.now():
convert a _PyTime_t timestamp to a (secs, us) tuple where secs type is time_t.
It allows to support dates after the year 2038 on Windows.

Enhance also _PyTime_AsTimeval_impl() to detect overflow on the number of
seconds when rounding the number of microseconds.

* test_eintr: support verbose mode, don't redirect eintr_tester output into
  a pipe
* eintr_tester: replace os.fork() with subprocess to have a cleaner child
  process (ex: don't inherit setitimer())
* eintr_tester: kill the process if the unit test fails
* test_open/test_os_open(): write support.PIPE_MAX_SIZE bytes instead of
  support.PIPE_MAX_SIZE*3 bytes

import_init() imports the "_imp" module, not the "imp" module.

format_stack(), and extract_stack() called without arguments.

format_stack(), and extract_stack() called without arguments.

ProactorEventLoop now supports SSL.

Reported by Jakub Wilk.

Reported by Jakub Wilk.

Add an unit test on os.waitpid()

Fix the regex to support the version 7.10: minor version with two digits

Patch by me and Elvis Pranskevichus

(we'll make a couple more commits tomorrow before release)

Patch by Elvis Pranskevichus

Patch by TAKASE Arihiro.