diff: teach diff to display submodule difference with an inline diff

2016-09-01T01:07:10Z

Teach git-diff and friends a new format for displaying the difference of a submodule. The new format is an inline diff of the contents of the submodule between the commit range of the update. This allows the user to see the actual code change caused by a submodule update. Add tests for the new format and option. Signed-off-by: Jacob Keller Signed-off-by: Junio C Hamano

git/t/t4060-diff-submodule-option-diff-format.sh, branch v2.12.2

diff: teach diff to display submodule difference with an inline diff