Merge branch 'sp/reflog' into next

* sp/reflog:
  Enable ref log creation in git checkout -b.
  Create/delete branch ref logs.
  Include ref log detail in commit, reset, etc.
  Change order of -m option to update-ref.
  Correct force_write bug in refs.c
  Change 'master@noon' syntax to 'master@{noon}'.
  Log ref updates made by fetch.
  Force writing ref if it doesn't exist.
  Added logs/ directory to repository layout.
  General ref log reading improvements.
  Fix ref log parsing so it works properly.
  Support 'master@2 hours ago' syntax
  Log ref updates to logs/refs/<ref>
  Convert update-ref to use ref_lock API.
  Improve abstraction of ref lock/write.

diff --cc Documentation/git-branch.txt
Simple merge

diff --cc Documentation/git-checkout.txt
index d82efc0,0643943..fbdbadc
--- 1/Documentation/git-checkout.txt
--- 2/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@@ -35,11 -35,13 +35,16 @@@ OPTION
        Force a re-read of everything.
  
  -b::
 -      Create a new branch and start it at <branch>.
 +      Create a new branch named <new_branch> and start it at
 +      <branch>.  The new branch name must pass all checks defined
 +      by gitlink:git-check-ref-format[1].  Some of these checks
 +      may restrict the characters allowed in a branch name.
  
+ -l::
+       Create the new branch's ref log.  This activates recording of
+       all changes to made the branch ref, enabling use of date
+       based sha1 expressions such as "<branchname>@{yesterday}".
+ 
  -m::
        If you have local modifications to one or more files that
        are different between the current branch and the branch to

diff --cc cache.h
Simple merge

diff --cc git-am.sh
Simple merge

diff --cc git-commit.sh
Simple merge

diff --cc http-fetch.c
Simple merge