add orElse function to maybe

Maybe.h

@@ -74,6 +74,14 @@ namespace Framework
                 return Maybe<R>::empty();
         }
 
+        T orElse(T elseValue)
+        {
+			if (set)
+				return value;
+			else
+				return elseValue;
+		}
+
         T operator->()
         {
             assert(set);