Merge branch 'ba/clone-remote-submodules'

"git clone --recurse-submodules" learned to set up the submodules
to ignore commit object names recorded in the superproject gitlink
and instead use the commits that happen to be at the tip of the
remote-tracking branches from the get-go, by passing the new
"--remote-submodules" option.

* ba/clone-remote-submodules:
  clone: add `--remote-submodules` flag

diff --cc builtin/clone.c
Simple merge