selinux: add support for xperms in conditional policies

selinux: add support for xperms in conditional policies

Add support for extended permission rules in conditional policies.
Currently the kernel accepts such rules already, but evaluating a
security decision will hit a BUG() in
services_compute_xperms_decision().  Thus reject extended permission
rules in conditional policies for current policy versions.

Add a new policy version for this feature.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>