Merge branch 'master' into jc/fmt-patch

Merge branch 'master' into jc/fmt-patch

* master:
  Split up builtin commands into separate files from git.c
  git-log produces no output
  fix pack-object buffer size
  mailinfo: decode underscore used in "Q" encoding properly.
  Reintroduce svn pools to solve the memory leak.
  pack-objects: do not stop at object that is "too small"
  git-commit --amend: two fixes.
  get_tree_entry(): make it available from tree-walk
  sha1_name.c: no need to include diff.h; tree-walk.h will do.
  sha1_name.c: prepare to make get_tree_entry() reusable from others.
  get_sha1() shorthands for blob/tree objects
  pre-commit hook: complain about conflict markers.
  git-merge: a bit more readable user guidance.
  diff: move diff.c to diff-lib.c to make room.
  git log: don't do merge diffs by default
  Allow "git repack" users to specify repacking window/depth
  Document git-clone --reference
  Fix filename scaling for binary files
  Fix uninteresting tags in new revision parsing

Conflicts:

    Adjusted the addition of fmt-patch to match the recent split
    from git.c to builtin.log.c.