Add total count and iteration count to forall environment

For long-running forall commands sometimes it's useful to know which
iteration is currently running. Add REPO_I and REPO_COUNT environment
variables to reflect the current iteration count as well as the total
number of iterations so that the user can build simple status
indicators.

Example:

    $ repo forall -c 'echo $REPO_I / $REPO_COUNT; git gc'
    1 / 579
    Counting objects: 41, done.
    Delta compression using up to 8 threads.
    Compressing objects: 100% (19/19), done.
    Writing objects: 100% (41/41), done.
    Total 41 (delta 21), reused 41 (delta 21)
    2 / 579
    Counting objects: 53410, done.
    Delta compression using up to 8 threads.
    Compressing objects: 100% (10423/10423), done.
    Writing objects: 100% (53410/53410), done.
    Total 53410 (delta 42513), reused 53410 (delta 42513)
    3 / 579
    ...

Change-Id: I9f28b0d8b7debe423eed3b4bc1198b23e40c0c50
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

0 files changed, 0 insertions, 0 deletions