contrib: require Python 3.6 for byteify-strings.py This script makes use of `token.COMMENT`, which apparently isn't present until Python 3.6. So make the script and its test conditional on Python 3.6.

demandimportpy3: only use lazy extension loader on Python 3.6+ There was an inline comment denoting a bug in the lazy extension loader on Python 3.5 which prevents it from working there. But the code was not conditional on the Python version. The result of this was a myriad of failures on Python 3.5 due to getattr() and friends not working on lazy extension modules. By making extension modules non-lazy on Python 3.5, we reduce the number of test failures from 48 to 22 on that Python version.

ui: flush before prompting for input with readline I was using `hg absorb` with Python 3 and noticed that the prompt was appearing without any output about what would be done. After I answered the prompt, the output was printed to stdout. This appears to be a buffering difference between Python 2 and Python 3. To work around it, this commit adds an explicit flush() before calling the raw input function when readline is used.

histedit: restore hex nodeids to be 12 digits long I accidentally switched from 12 digits to 40 digits while making the code py3-compatible. Thanks to Yuya for noticing. Differential Revision: https://phab.mercurial-scm.org/D7200

tests: fix typo "includfe" Differential Revision: https://phab.mercurial-scm.org/D7180

py3: fix fsmonitor's _watchmantofsencoding exception message encoding Differential Revision: https://phab.mercurial-scm.org/D7190

py3: use native strings as keys into **opts in chistedit Now you should be able to successfully confirm your histedit plan (at least in the case I tried). Even continuing after conflicts and finishing the histedit worked. Differential Revision: https://phab.mercurial-scm.org/D7186