Merge branch 'stable-2.13' into stable-2.14

* stable-2.13:
  Deprecate plugin

Change-Id: I556554a60bfd6f979a9ccfe151bd4f39ba6aea4b
tree: d539b0e1502c2a0b2663f312e396505474f6ffe6
  1. .buckconfig
  2. .gitignore
  3. README-THIS-REPO-IS-DEPRECATED.txt