Merge branch 'stable-3.1' into 'master'

* origin/stable-3.1:
  Remove unused properties
  example-webLinkProject: Remove unused dependencies
  Refactor poms and build parent pom
  Update bazlets to latest 3.1 and maven build to 3.1.8
  Update bazlets to latest 3.0 and maven build to 3.0.13
  Update bazlets to latest 2.16 and maven build to 2.16.22

Change-Id: I4d166d4748ea63648278a6282218f046ac0e25d4