Merge branch 'js/add-p-diff-parsing-fix'

Merge branch 'js/add-p-diff-parsing-fix'

Those who use diff-so-fancy as the diff-filter noticed a regression
or two in the code that parses the diff output in the built-in
version of "add -p", which has been corrected.

* js/add-p-diff-parsing-fix:
  add -p: ignore dirty submodules
  add -p: gracefully handle unparseable hunk headers in colored diffs
  add -p: detect more mismatches between plain vs colored diffs