Merge branch 'jc/missing-ref-store-fix'

We've left the command line parsing of "git log :/a/b/" broken for
about a full year without anybody noticing, which has been
corrected.

* jc/missing-ref-store-fix:
  repository: mark the "refs" pointer as private
  sha1-name: do not assume that the ref store is initialized

diff --cc refs.c
Simple merge

diff --cc repository.h
Simple merge

diff --cc sha1-name.c
Simple merge