Allow to enable_vnc for provisioned VMs.

_modules/virtng.py

     else:
         context['boot_dev'] = ['hd']
 
+    if 'enable_vnc' in kwargs:
+        context['enable_vnc'] = kwargs['enable_vnc']
+        log.info('VNC enabled: {0}.'.format(kwargs['enable_vnc']))
     if 'serial_type' in kwargs:
         context['serial_type'] = kwargs['serial_type']
     if 'serial_type' in context and context['serial_type'] == 'tcp':

salt/control/virt.sls

 {%- set rng = cluster.rng %}
 {%- endif %}
 
+{%- if cluster.enable_vnc is defined and cluster.enable_vnc %}
+{%- set enable_vnc = True %}
+{%- else %}
+{%- set enable_vnc = False %}
+{%- endif %}
+
+
 {%- for node_name, node in cluster.node.iteritems() %}
 
 {%- if node.name is defined %}
       seed: True
       serial_type: pty
       console: True
+      {%- if node.enable_vnc is defined %}
+      enable_vnc: {{ node.enable_vnc }}
+      {%- else %}
+      enable_vnc: {{ enable_vnc }}
+      {%- endif %}
       {%- if node.img_dest is defined %}
       img_dest: {{ node.img_dest }}
       {%- endif %}