Merge branch 'devel-2.5'

* devel-2.5:
  Revert "Added SPICE TLS option and related cert paths"
  Revert "Implementation of TLS-protected SPICE connections"
  Revert "Updated man pages with new SPICE TLS options"
  Revert "Add tls_ciphers and use_vdagent options"

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>