Merge branch 'sp/reflog'
* sp/reflog:
fetch.c: do not pass uninitialized lock to unlock_ref().
Test that git-branch -l works.
Verify git-commit provides a reflog message.
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.