Merge branch 'tc/clone-single-revision'

"git clone" learned to make a shallow clone for a single commit that is not necessarily be at the tip of any branch. * tc/clone-single-revision: builtin/clone: teach git-clone(1) the --revision= option parse-options: introduce die_for_incompatible_opt2() clone: introduce struct clone_opts in builtin/clone.c clone: add tags refspec earlier to fetch refspec clone: refactor wanted_peer_refs() clone: make it possible to specify --tags clone: cut down on global variables in clone.c