Merge branch 'stable-2.3'

By Fredrik Luthander (15) and others
via gerrit code review (7) and Edwin Kempin (1)
* stable-2.3: (25 commits)
  Fix case check for project name so that symlinks work again
  Move note about changing approval categories to the correct section
  Fix spelling mistake in access control documentation
  Gerrit 2.3 ReleaseNotes
  Fix link in show caches documentation
  Access control documentation: Administrator example role
  Access control documentation: Project owner example role
  Access control documentation: Integrator example role
  Access control documentation: CI system example role
  Access control documentation: Capability view conn. & queue
  Access control documentation: Developer example role
  Access control documentation: Capability replication and view caches
  Access control documentation: Kill and priority capabilities
  Access control documentation: Flush caches capability
  Access control documentation: Example roles introduced
  Add missing header for suggest.accounts documentation
  Add visible-to-all flag in the documentation for cmd-create-group
  Access control documentation: Create group and project
  Gerrit 2.3 ReleaseNotes
  Fix NPEs looking up groups by UUID in GroupCache
  ...

Conflicts:
	Documentation/config-gerrit.txt
	gerrit-server/src/main/java/com/google/gerrit/server/git/RepositoryCaseMismatchException.java

Change-Id: Ica57067e0978904875440421f0aaf06ff9051fcc