histedit: renaming parts to which _histedit was split
I recently broke _histedit into multiple functions, each of which
had 'action' in its name. This is a little bit confusing since 'action'
is the word for an individual histedit plan item (such as edit or pick).
To avoid this confusion, these functions are now renamed to contain
'histedit' as part of their names.
To run the tests, do:
cd tests/
python run-tests.py
See https://mercurial-scm.org/wiki/WritingTests for
more information on writing tests.