rename: return error status if any rename/copy failed
Ever since
447ea621e50e (copy: propagate errors properly, 2007-12-06),
we have returned an error status if the source file did not
exist. That commit did not return error status for any other errors,
and it's unclear if that was on purpose or not. It seems to me like we
should return an error in the other cases to, so that's what this
patch does.
Differential Revision: https://phab.mercurial-scm.org/D4419
rename: emit hint about using --after consistently
Both the code and the message for the case where the source file was
missing was inconsistent with the other similar messages.
Differential Revision: https://phab.mercurial-scm.org/D4418