Merge tag 'keys-fixes-20140916' into keys-next

Merge in keyrings fixes, at least some of which later patches depend on:

 (1) Reinstate the production of EPERM for key types beginning with '.' in
     requests from userspace.

 (2) Tidy up the cleanup of PKCS#7 message signed information blocks and fix a
     bug this made more obvious.

Signed-off-by: David Howells <dhowells@redhat.coM>