The patches below clean-up sHype-related file names in the tools subtree

The patches below clean-up sHype-related file names  in the tools subtree
and security policy-versioning and data structures in the xen subtree
(ACM):

 *  the very generic tools directory name "policy"  is changed to
    "security" and the included "policy_tool" to "secpol_tool"

 * the single constant POLICY_INTERFACE_VERSION is replaced
   by ACM_INTERFACE_VERSION; the security policy headers are
   versioned independently since the policy can be supplied
   at boot time instead of through the  hypervisor interface

Signed-off-by: Reiner Sailer <sailer@watson.ibm.com>
Signed-off-by: Steven Hand <steven@xensource.com>