trunk: Unified labeled networking policy from Paul Moore.

trunk: Unified labeled networking policy from Paul Moore.

The latest revision of the labeled policy patches which enable both labeled
and unlabeled policy support for NetLabel.  This revision takes into account
Chris' feedback from the first version and reduces the number of interface
calls in each domain down to two at present: one for unlabeled access, one for
NetLabel access.  The older, transport layer specific interfaces, are still
present for use by third-party modules but are not used in the default policy
modules.

trunk: Use netmsg initial SID for MLS-only Netlabel packets, from Paul Moore.

This patch changes the policy to use the netmsg initial SID as the "base"
SID/context for NetLabel packets which only have MLS security attributes.
Currently we use the unlabeled initial SID which makes it very difficult to
distinquish between actual unlabeled packets and those packets which have MLS
security attributes.