Adding docs for noVNC (apache#156)

Author: davidjumani

source/adminguide/systemvm.rst

@@ -157,13 +157,21 @@ to the VNC port made available via the hypervisor for the console of the
 guest. Both the administrator and end user web UIs offer a console
 connection.
 
-Clicking a console icon brings up a new window. The AJAX code downloaded
+Clicking a console icon brings up a new window. The console viewer
 into that window refers to the public IP address of a console proxy VM.
 There is exactly one public IP address allocated per console proxy VM.
-The AJAX application connects to this IP. The console proxy then proxies
+The viewer application connects to this IP. The console proxy then proxies
 the connection to the VNC port for the requested VM on the Host hosting
 the guest.
 
+Since 4.15, noVNC has been integrated into the console proxy and is the
+default viewer. It inherently supports multiple keyboard layouts configured
+in the guest virtual machine. Additionally, it can scale the display as
+well as paste into the console.
+
+noVNC is set as the default console viewer which be changed via the
+"novnc.console.default" global setting, which is set to true by default.
+
 .. note:: 
    The hypervisors will have many ports assigned to VNC usage so that 
    multiple VNC sessions can occur simultaneously.