Merge changes from topic 'list-branches-cleanup'

* changes:
  ListBranches: Factor out method for listing all branches
  ListBranches: Handle HEAD and refs/meta/config in the Comparator
  ListBranches: Use FluentIterable for filter, start, and limit
  ListBranches: Remove unnecessary finals
  ListBranches: Don't ignore IOExceptions reading refs
  ListBranches: Be more precise about collection sizes
  ListBranches: Use Repository in try-with-resources