The result of 'hg rm' + 'hg rename' disagreed with the one from
'hg rename --force'. We align them on 'hg move --force' because it agrees with
what 'hg status' says after the commit.

Stopping reporting a modified file as added puts an end to the hg revert confusion in this
situation (issue4458).

However, reporting the file as modified also prevents revert from restoring the copy
source. We fix this in a later changeset.

Git diff also stop reporting the add in the middle of the chain as add. Not
sure how important (and even wrong) it is.