Highlight the enumerators using the Static `char format'.

The new `Static' format will be used to mark all the static members, e.g. enumerators,
static functions, and static class members, but right now, it is used only for enumerators.

src/plugins/cppeditor/cppsemanticinfo.h

@@ -52,6 +52,7 @@ public:
             Type = 0,
             Local,
             Field,
+            Static,
             VirtualMethod
         };