TW-1827: Extract annotations from a task

- Thanks to Ryan.

src/DOM.cpp

@@ -167,6 +167,7 @@ bool getDOM (const std::string& name, Variant& value)
 //   <date>.second
 //
 // Annotations (entry is a date):
+//   annotations.count
 //   annotations.<N>.entry
 //   annotations.<N>.description
 //
@@ -298,6 +299,12 @@ bool getDOM (const std::string& name, const Task& task, Variant& value)
     }
   }
 
+  if (ref.data.size () && size == 2 && elements[0] == "annotations" && elements[1] == "count")
+  {
+    value = Variant (static_cast<int> (ref.getAnnotationCount ()));
+    return true;
+  }
+
   if (ref.data.size () && size == 3 && elements[0] == "annotations")
   {
     auto annos = ref.getAnnotations ();