Merge branch 'fg/submodule-non-ascii-path'

Many "git submodule" operations do not work on a submodule at a
path whose name is not in ASCII.

* fg/submodule-non-ascii-path:
  t7400: test of UTF-8 submodule names pass under Mac OS
  handle multibyte characters in name

diff --cc git-submodule.sh
Simple merge

diff --cc t/t7400-submodule-basic.sh
Simple merge