Merge 9c9ceecc47 into master

* commit 9c9ceecc47e:
  Fix standalone build, reference plugin API 2.13.9
  Revert "Add support for Bazel in Gerrit tree build"

This merge uses "-s ours" strategy, which keeps master unchanged.  We
don't want these two changes in master.  The purpose of this merge is to
create a merge-base for the follow-up merges.

Change-Id: I408f0d93cb4085411a96e74aafbd9c6c5eae8805
tree: 96e860d83493ac25d3b84f9f64d193eb0342e098
  1. lib/
  2. src/
  3. .buckconfig
  4. .gitignore
  5. BUCK
  6. BUILD
  7. LICENSE
  8. pom.xml
  9. VERSION