Merge branch 'ds/sparse-apply-add-p'

Merge branch 'ds/sparse-apply-add-p'

"git apply" and "git add -i/-p" code paths no longer unnecessarily
expand sparse-index while working.

* ds/sparse-apply-add-p:
  p2000: add performance test for patch-mode commands
  reset: integrate sparse index with --patch
  git add: make -p/-i aware of sparse index
  apply: integrate with the sparse index