Add a flatbuffer merge function

The second value wins.  Vectors get appended.  Nested objects get both
merged.

Change-Id: I1cb3f65b57d7cf219fca3c6d8dbb8418f8a0d697
diff --git a/aos/json_to_flatbuffer.fbs b/aos/json_to_flatbuffer.fbs
index 9743345..2e90a53 100644
--- a/aos/json_to_flatbuffer.fbs
+++ b/aos/json_to_flatbuffer.fbs
@@ -14,13 +14,14 @@
 
 table Application {
   name:string;
+  priority:int;
   maps:[Map];
 }
 
 table Configuration {
   locations:[Location] (id: 0);
   maps:[Map] (id: 1);
-  applications:[Application] (id: 2);
+  apps:[Application] (id: 2);
   imports:[string] (id: 3);
 
   // 8 bit: byte ubyte bool
@@ -68,6 +69,11 @@
 
   // And a simple nested application.
   single_application:Application (id: 28);
+
+  // TODO(austin): enum
+
+  // And nest this object to get some crazy coverage.
+  nested_config:Configuration (id: 29);
 }
 
 root_type Configuration;