Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Update javamelody-core to 1.75.0
  Bazel: Include eclipse-out directory in .bazelignore
  Add explanatory comment to empty BUILD file(s)

Change-Id: I6932dac91a1df7a01b26e0186ddcb840c5680b8e