view CONTRIBUTING @ 42088:770e87999701

chistedit: use default curses colours

Terminals will define default colours (for example, white text on
black background), but curses doesn't obey those default colours
unless told to do so.

Calling `curses.use_default_colors` makes curses obey the default
terminal colours. One of the most obvious effects is that this allows
transparency on terminals that support it.

This also brings chistedit closer in appearance to crecord, which also
uses default colours.

The call may error out if the terminal doesn't support colors, but as
far as I can tell, everything still works. If we need a more careful
handling of lack of colours, blame me for not doing it now.

Our full contribution guidelines are in our wiki, please see:

https://www.mercurial-scm.org/wiki/ContributingChanges

If you just want a checklist to follow, you can go straight to

https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist

If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).