take relative paths from the command line.

 * "git check-attr" learned an "--all" option to list the attributes for a
   given path.

 * "git checkout" (both the code to update the files upon checking out a
   different branch and the code to checkout a specific set of files) learned
   to stream the data from object store when possible, without having to
   read the entire contents of a file into memory first. An earlier round
   of this code that is not in any released version had a large leak but
   now it has been plugged.

 * "git clone" can now take a "--config key=value" option to set the
   repository configuration options that affect the initial checkout.

 * "git commit <paths>..." now lets you feed relative pathspecs that
   refer to outside your current subdirectory.

 * "git diff --stat" learned a --stat-count option to limit the output of
   a diffstat report.

 * "git diff" learned a "--histogram" option to use a different diff
   generation machinery stolen from jgit, which might give better
   performance.

 * "git diff" had a weird worst case behaviour that can be triggered
   when comparing files with potentially many places that could match.

 * "git fetch", "git push" and friends no longer show connection
   errors for addresses that couldn't be connected to when at least one
   address succeeds (this is arguably a regression but a deliberate
   one).

 * "git grep" learned "--break" and "--heading" options, to let users mimic
   the output format of "ack".

 * "git grep" learned a "-W" option that shows wider context using the same
   logic used by "git diff" to determine the hunk header.

 * Invoking the low-level "git http-fetch" without "-a" option (which
   git itself never did--normal users should not have to worry about
   this) is now deprecated.

 * The "--decorate" option to "git log" and its family learned to
   highlight grafted and replaced commits.

 * "git rebase master topci" no longer spews usage hints after giving
   the "fatal: no such branch: topci" error message.

 * The recursive merge strategy implementation got a fairly large
   fix for many corner cases that may rarely happen in real world
   projects (it has been verified that none of the 16000+ merges in
   the Linux kernel history back to v2.6.12 is affected with the
   corner case bugs this update fixes).

 * "git stash" learned an "--include-untracked option".

 * "git submodule update" used to stop at the first error updating a
   submodule; it now goes on to update other submodules that can be
   updated, and reports the ones with errors at the end.

 * "git push" can be told with the "--recurse-submodules=check" option to
   refuse pushing of the supermodule, if any of its submodules'
   commits hasn't been pushed out to their remotes.

 * "git upload-pack" and "git receive-pack" learned to pretend that only a
   subset of the refs exist in a repository. This may help a site to
   put many tiny repositories into one repository (this would not be
   useful for larger repositories as repacking would be problematic).

 * "git verify-pack" has been rewritten to use the "index-pack" machinery
   that is more efficient in reading objects in packfiles.

 * test scripts for gitweb tried to run even when CGI-related perl modules
   are not installed; they now exit early when the latter are unavailable.

Also contains various documentation updates and minor miscellaneous
changes.


Fixes since v1.7.6
------------------

Unless otherwise noted, all fixes in the 1.7.6.X maintenance track are
included in this release.

 * "git branch -m" and "git checkout -b" incorrectly allowed the tip
   of the branch that is currently checked out updated.