Change test_time.test_monotonic() to test only the lower bound of elapsed time
after a sleep command rather than the upper bound. This prevents unnecessary
test failures on slow buildbots. Patch by Victor Stinner.

xlc compiler doesn't support "-D define" flag only "-Ddefine".

Co-authored-by: Felipe <felipe.nospam.ochoa@gmail.com>

"sychronization" -> "synchronization"

PyUnicode_AsUnicodeAndSize() -> PyUnicode_AsWideChar()

bpo-30485: Change the prefix for defining the default namespace in ElementPath from None to '' since there is existing code that uses that and it's more convenient to have an all-string-keys dict (e.g. when sorting items etc.). (#12860)

# [bpo-36651](https://bugs.python.org/issue36651): Fixed Asyncio Event Loop documentation inconsistency  

In the documentation for the call_later and the call_at methods there is a note which says that the delay cannot be longer than a day, but both methods have a note saying that this limitation was removed in Python 3.8
Here I fixed this issue by removing the pre-exising note and added a versionchanged. 

To test my changes I have rebuilt the documentation with ```make html```. I did not have any errors and the effected page displayed correctly on a browser.



https://bugs.python.org/issue36651

Add a new _testinternalcapi module to test the internal C API.

Move _Py_GetConfigsAsDict() function to the internal C API:
_testembed now uses _testinternalcapi to access the function.

This paragraph doesn't seem to be a part of code, but merged into previous code block.