histedit: remove "chistedit" mention from interface
"chisted" is internal jargon. The end user should not need to be aware
that it's different from histedit.
revset: improve documentation on expectsize()
This is a follow-up patch to D5813. It improves the documentation of
`expectsize(set, size)`.
Differential Revision: https://phab.mercurial-scm.org/D5953