Nova is gaining the ability to run TLS over the connection between the
novnc proxy service and the QEMU/KVM compute node VNC server.
This adds a new config param - 'NOVA_CONSOLE_PROXY_COMPUTE_TLS=True' -
which instructs devstack to configure libvirt/QEMU to enable TLS for the
VNC server, and to configure the novncproxy to use TLS when connecting.
NB this use of TLS is distinct from use of TLS for the public facing API
controlled by USE_SSL, they can be enabled independently.
This is done in a generic manner so that it is easy to extend to cover
use of TLS with the SPICE and serial console proxy services too.
Change-Id: Ib29d3f5f18533115b9c51e27b373e92fc0a28d1a
Depends-on: I9cc9a380500715e60bd05aa5c29ee46bc6f8d6c2
Implements bp: websocket-proxy-to-host-security
e9870eb18d