audit: address x-compile issues

The previous approach works well for modern hosts but older ones still
require the pre-gen'd header files to behave nicely in a x-compile
environment.  So we generate them, patch them in and remove the bits of
the Makefile that may take it upon itself to re-gen them again.

Signed-off-by: Joe MacDonald <joe@deserted.net>
Add recipe to build the MCS refpolicy.

This is the default policy type used by most (all?) distros that
support SELinux.

Signed-off-by: Philip Tricca <flihp@twobit.us>
Signed-off-by: Joe MacDonald <joe@deserted.net>
Move common POLICY_* variables to refpolicy_common.inc

Use default assignment to allow variables to be overriden by recipes
that include refpolicy_common.inc

Signed-off-by: Philip Tricca <flihp@twobit.us>
Signed-off-by: Joe MacDonald <joe@deserted.net>
refpolicy-mcs: Use default variables from refpolicy_common.inc

Signed-off-by: Philip Tricca <flihp@twobit.us>
Signed-off-by: Joe MacDonald <joe@deserted.net>
refpolicy-mls: Use default variables from refpolicy_common.inc

Signed-off-by: Philip Tricca <flihp@twobit.us>
Signed-off-by: Joe MacDonald <joe@deserted.net>
refpolicy-standard: Use default variables from refpolicy_common.inc

Signed-off-by: Philip Tricca <flihp@twobit.us>
Signed-off-by: Joe MacDonald <joe@deserted.net>
Merge remote-tracking branch 'upstream/master'

Conflicts:
	recipes-security/refpolicy/refpolicy_common.inc