[PATCH 0/11] Misc. pull/merge/am improvements

This series of patches is a group of minor interface and performance improvements for am/pull/rebase.

  1 Use GIT_REFLOG_ACTION environment variable instead.
  2 Honor GIT_REFLOG_ACTION in git-rebase.

    These two replace my prior 2 patch series in the same area.

  3 Use branch names in 'git-rebase -m' conflict hunks.

    This is a UI improvement to show better conflicts out of rebase.

  4 Ensure `git-pull` fails if `git-merge` fails.

    Trivial fix to make git-pull more friendly to other scripts.

  5 Honor pull.{twohead,octopus} in git-merge.
  6 Allow git-merge to select the default strategy.

    This moves the default merge strategy selection into git-merge,
    making it part of that tool rather than git-pull.  This makes
    it possible to get the same behavior from `git merge foo` as
    you already get from `git pull . foo`.

  7 Avoid git-fetch in `git-pull .` when possible.

    This is a performance improvement for pull, and offers some
    other nice benefits (see patch).

  8 Move better_branch_name above get_ref in merge-recursive.
  9 Allow merging bare trees in merge-recursive.
 10 Use merge-recursive in git-am -3.

    These three switch to merge-recursive in git-am, see patch 10's
    message for the benefits.

 11 Improve merge performance by avoiding in-index merges.

    This is a general performance improvement for all two-headed
    merges which might use merge-recursive.

I'd like to see these appear in v1.5.0, but we're getting close to the release so I can understand if they get delayed.