rerere: record (or avoid misrecording) resolved, skipped or aborted rebase/am

rerere: record (or avoid misrecording) resolved, skipped or aborted rebase/am

Data in rr-cache isn't valid after a patch application is
skipped or and aborted, so our next commit could be misrecorded
as a resolution of that skipped/failed commit, which is wrong.

git-am --skip, git-rebase --skip/--abort will automatically
invoke git-rerere clear to avoid this.

Also, since git-am --resolved indicates a resolution was
succesful, remember to run git-rerere to record the resolution
(and not surprise the user when the next commit is made).

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>