[PATCH] [checkout-index] Give names to stages

One can now say "git-checkout-index --stage=ours ..."  or
"git-checkout-index --stage=theirs ...", instead of having
to remember the corresponding number assigned to each stage.

Signed-off-by: Luben Tuikov <redacted>
---
 builtin-checkout-index.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

I find this quite helpful when resolving.