(SAD): write doc about IServices::getLockedXXX() and deprecation of regular IServices::get[In,out]put

Description

The method IServices::getInput(), IServices::getOutput(), IServices::getInOut() has been deprecated in favor of IServices::getLockedInput(), IServices::getLockedOutput(), IServices::getLockedInOut() and IServices::getWeakInput(), IServices::getWeakOutput(), IServices::getWeakInOut() that allow transparent locking for conccurent access and buffer serialization.

Documentation should reflect this change.