Adds get_console_connect_info API

Implements: blueprint hyper-v-rdp-console

Currently graphical console access to Nova instances is limited to
clients which are part of Nova itself (novnc, xvpvnc, spice-html5).
The mentioned clients verify the validity of a console access token
with the following private API:
nova.consoleauth.rpcapi.ConsoleAuthAPI.check_token

The usage of a private API precludes the possibility of employing
external graphical console clients, including FreeRDP-WebConnect, used
to connect to Hyper-V instances via RDP.

This change adds a public API method that wraps the aforementioned
check_token private API. This allows external clients to obtain the
necessary protocol connection information by providing a token
previously obtained with calls to get_vnc_console, get_spice_console
or get_rdp_console.

Includes V2 and V3 API implementations.

Change-Id: Idd1e4f57b16bd1488f3b72bb064cef51321a7c79
Sync latest Guru Meditation Reports from Oslo

Nova fails to start on Windows due to non portable signal handling
(SIGUSR1) employed in this patch.

This patch enables the reporting feature only if signal is available
on the current platform.

Oslo commit: d3a285e33fa936cec5d14dfefa20dc03cc90ac18

Closes-Bug: #1286528

Change-Id: I070ab57b18b2bc43df5ec84c51ccb86be1ff0d2a
Merge "Sync latest Guru Meditation Reports from Oslo"
Merge "Adds get_console_connect_info API"