Merge branch 'stable-2.7'

* stable-2.7:
  Fix spelling errors in access-control.txt
  Access control documentation: Formatting
  Access control documentation: Clean up of categories
  Access Control Documentation: Explain special and magic refs
  Set core plugins to correct revisions for 2.6-rc2
  Update developer instructions for cloning the Gerrit project
  Fix Windows build

Conflicts:
	Documentation/access-control.txt

Change-Id: I1ee212d357f0da6d006c5fef9427a4b7138c7536