Merge branch 'stable-3.1' into stable-3.2

* stable-3.1:
  Exclude special refs from fetch calls
  Parallelise REST API fetch calls

Change-Id: I385d06acc60f7734101cf6fcd9a810cd98ee63b2
tree: 5f1f6a258b5ce2177fe38085a174286c4623218d
  1. src/
  2. BUILD
  3. Jenkinsfile
  4. LICENSE