git reset without argument displays a summary of the local modification,
like this:
$ git reset
Makefile: locally modified
Some people have problems with this; they look like an error message.
This patch makes its output mimic how "git checkout $another_branch"
reports the paths with local modifications. "git add --refresh --verbose"
is changed in the same way.
It also adds a header to make it clear that the output is informative,
and not an error.