conflicted state works even when you already ran "git add path" and
   resolved the conflicts.

 * "git commit --date='<date>'" can be used to override the author date
   just like "git commit --author='<name> <email>'" can be used to
   override the author identity.

 * "git commit --no-status" can be used to omit the listing of the index
   and the work tree status in the editor used to prepare the log message.

 * "git commit" warns a bit more aggressively until you configure user.email,
   whose default value almost always is not (and fundamentally cannot be)
   what you want.

 * "git difftool" has been extended to make it easier to integrate it
   with gitk.

 * "git fetch --all" can now be used in place of "git remote update".

 * "git grep" does not rely on external grep anymore.  It can use more than
   one thread to accelerate the operation.

 * "git grep" learned "--quiet" option.

 * "git log" and friends learned "--glob=heads/*" syntax that is a more
   flexible way to complement "--branches/--tags/--remotes".

 * "git merge" learned to pass options specific to strategy-backends.  E.g.

    - "git merge -Xsubtree=path/to/directory" can be used to tell the subtree
      strategy how much to shift the trees explicitly.

    - "git merge -Xtheirs" can be used to auto-merge as much as possible,
      while discarding your own changes and taking merged version in
      conflicted regions.

 * "git push" learned "git push origin --delete branch", a syntactic sugar
   for "git push origin :branch".

 * "git push" learned "git push --set-upstream origin forker:forkee" that
   lets you configure your "forker" branch to later pull from "forkee"
   branch at "origin".

 * "git rebase --onto A...B" means the history is replayed on top of the
   merge base between A and B.

 * "git rebase -i" learned new action "fixup" that squashes the change
   but does not affect existing log message.

 * "git rebase -i" also learned --autosquash option that is useful
   together with the new "fixup" action.

 * "git remote" learned set-url subcommand that updates (surprise!) url
   for an existing remote nickname.

 * "git rerere" learned "forget path" subcommand.  Together with "git
   checkout -m path" it will be useful when you recorded a wrong
   resolution.

 * Use of "git reset --merge" has become easier when resetting away a
   conflicted mess left in the work tree.

 * "git rerere" had rerere.autoupdate configuration but there was no way
   to countermand it from the command line; --no-rerere-autoupdate option
   given to "merge", "revert", etc. fixes this.

 * "git status" learned "-s(hort)" output format.

(developers)

 * The infrastructure to build foreign SCM interface has been updated.

 * Many more commands are now built-in.

 * THREADED_DELTA_SEARCH is no more.  If you build with threads, delta
   compression will always take advantage of it.

Fixes since v1.6.6
------------------

All of the fixes in v1.6.6.X maintenance series are included in this
release, unless otherwise noted.

 * "git branch -d branch" used to refuse deleting the branch even when
   the branch is fully merged to its upstream branch if it is not merged
   to the current branch.  It now deletes it in such a case.

 * "filter-branch" command incorrectly said --prune-empty and --filter-commit
   were incompatible; the latter should be read as --commit-filter.

 * When using "git status" or asking "git diff" to compare the work tree
   with something, they used to consider that a checked-out submodule with
   uncommitted changes is not modified; this could cause people to forget
   committing these changes in the submodule before committing in the
   superproject. They now consider such a change as a modification and
   "git diff" will append a "-dirty" to the work tree side when generating
   patch output or when used with the --submodule option.