Move the fpdfsdk/include/javascript folder

This CL splits the IJavaScript.h file into the two inner classes and puts them
in the fpdfsdk/javascript folder.

Review URL: https://codereview.chromium.org/1847583004
diff --git a/fpdfsdk/javascript/global.cpp b/fpdfsdk/javascript/global.cpp
index 251e95b..fe974c7 100644
--- a/fpdfsdk/javascript/global.cpp
+++ b/fpdfsdk/javascript/global.cpp
@@ -9,17 +9,14 @@
 #include <vector>
 
 #include "core/fxcrt/include/fx_ext.h"
-#include "fpdfsdk/include/javascript/IJavaScript.h"
-#include "fpdfsdk/javascript/JS_Context.h"
 #include "fpdfsdk/javascript/JS_Define.h"
 #include "fpdfsdk/javascript/JS_EventHandler.h"
 #include "fpdfsdk/javascript/JS_GlobalData.h"
 #include "fpdfsdk/javascript/JS_Object.h"
 #include "fpdfsdk/javascript/JS_Value.h"
+#include "fpdfsdk/javascript/cjs_context.h"
 #include "fpdfsdk/javascript/resource.h"
 
-/* ---------------------------- global ---------------------------- */
-
 // Helper class for compile-time calculation of hash values in order to
 // avoid having global object initializers.
 template <unsigned ACC, wchar_t... Ns>