Rename Executor to JSExecutor

Summary:
* Cleanup some header files so we use more forward declarations
* Rename Executor to JSExecutor.h
* Move some typedefs to more appropriate locations

Reviewed By: mhorowitz

Differential Revision: D5301913

fbshipit-source-id: e75154797eb3f531d2f42a5e95409f4062b85f91

ReactCommon/cxxreact/CxxModule.h

@@ -1,23 +1,26 @@
 // Copyright 2004-present Facebook. All Rights Reserved.
 
-#ifndef FBXPLATMODULE
-#define FBXPLATMODULE
-
-#include <folly/dynamic.h>
+#pragma once
 
 #include <functional>
-
 #include <map>
 #include <tuple>
 #include <vector>
 
+#include <folly/dynamic.h>
+
 using namespace std::placeholders;
 
-namespace facebook { namespace react {
-  class Instance;
+namespace facebook {
+namespace react {
+
+class Instance;
+
 }}
 
-namespace facebook { namespace xplat { namespace module {
+namespace facebook {
+namespace xplat {
+namespace module {
 
 /**
  * Base class for Catalyst native modules whose implementations are
@@ -186,5 +189,3 @@ private:
 };
 
 }}}
-
-#endif