rust-changelog: made doc-comments more consistent
The most important is the one about `data_for_rev`, that looked like
a copy-paste leftover (got me confused first time I read this code, before
I actually learned there were both `Entry` and RevisionData`.
In the comment for the `struct`, "changelog" was probably more about
the format in general (as documented elsewhere) than as an identifier.
Some of the "Return something" had "of", half had "for".
#require symlink
https://bz.mercurial-scm.org/1438
$ hg init repo
$ cd repo
$ ln -s foo link
$ hg add link
$ hg ci -mbad link
$ hg rm link
$ hg ci -mok
$ hg diff -g -r 0:1 > bad.patch
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg import --no-commit bad.patch
applying bad.patch
$ hg status
R link
? bad.patch