The documentation is now global and its sources moved to the top-level
directory. Same goes for the know-problems-* and features-* files that
are now shared between all submodules.
This commit needs to be push in synchronization with change I0a342aea8d
in the ANOD specification repository.
Change-Id: If350f109ae6a40ae3e632bfa8491145aaab8a52f
TN: OA28-039
