Fixes and cleanups for missing lables

* Moved release notes to other pdf files. Building them as
  a separate job is not only pointless but also doesn't
  allow referencing other chapters with :ref tag from the
  release notes.

* Cleaned some broken references and labels.

Change-Id: I8029b6e165450214c01113818a29d9102a53cd30
Merge "Fixes and cleanups for missing lables"