Create a new libapparmor public function that allows external code to
split an AppArmor confinement context.
This is immediately useful for code that retrieves a D-Bus peer's
AppArmor confinement context using the
org.freedesktop.DBus.GetConnectionCredentials bus method.
https://launchpad.net/bugs/1430532
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>