AppArmor: core policy routines

The basic routines and defines for AppArmor policy.  AppArmor policy
is defined by a few basic components.
      profiles - the basic unit of confinement contain all the information
                 to enforce policy on a task

                 Profiles tend to be named after an executable that they
                 will attach to but this is not required.
      namespaces - a container for a set of profiles that will be used
                 during attachment and transitions between profiles.
      sids - which provide a unique id for each profile

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>