Merge branch 'jk/colors' into maint

"diff-highlight" (in contrib/) used to show byte-by-byte
differences, which meant that multi-byte characters can be chopped
in the middle.  It learned to pay attention to character boundaries
(assuming the UTF-8 payload).

* jk/colors:
diff-highlight: do not split multibyte characters

diff --cc contrib/diff-highlight/diff-highlight
Simple merge