hypervisor support matrix: add status "unknown"

When a new feature gets added to the hypervisor support matrix it
was not possible to state that the hypervisor did not make a support
statement yet. You had to choose between "complete", "partial" and
"missing" wich could be missleading.
This change set adds the status "unknown" which could make the
statements more precise.

Change-Id: If94fc772796742de88af5893839945834b9d3eb6

doc/ext/support_matrix.py

@@ -81,8 +81,10 @@ class SupportMatrixImplementation(object):
     STATUS_COMPLETE = "complete"
     STATUS_PARTIAL = "partial"
     STATUS_MISSING = "missing"
+    STATUS_UKNOWN = "unknown"
 
-    STATUS_ALL = [STATUS_COMPLETE, STATUS_PARTIAL, STATUS_MISSING]
+    STATUS_ALL = [STATUS_COMPLETE, STATUS_PARTIAL, STATUS_MISSING,
+                  STATUS_UKNOWN]
 
     def __init__(self, status=STATUS_MISSING, notes=None):
         # One of the status constants detailing the implementation
@@ -346,12 +348,14 @@ class SupportMatrixDirective(rst.Directive):
                 impltxt.append(implref)
 
                 status = ""
-                if impl.status == "complete":
+                if impl.status == SupportMatrixImplementation.STATUS_COMPLETE:
                     status = u"\u2714"
-                elif impl.status == "missing":
+                elif impl.status == SupportMatrixImplementation.STATUS_MISSING:
                     status = u"\u2716"
-                elif impl.status == "partial":
+                elif impl.status == SupportMatrixImplementation.STATUS_PARTIAL:
                     status = u"\u2714"
+                elif impl.status == SupportMatrixImplementation.STATUS_UKNOWN:
+                    status = u"?"
 
                 implref.append(nodes.literal(
                     text=status,

doc/source/_static/support-matrix.css

@@ -32,6 +32,11 @@
     font-weight: normal;
 }
 
+.sp_impl_unknown {
+    color: rgb(170, 170, 170);
+    font-weight: normal;
+}
+
 .sp_impl_summary {
     font-size: 2em;
 }