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/console.cpp b/fpdfsdk/javascript/console.cpp
index 4cce32d..a09fe4d 100644
--- a/fpdfsdk/javascript/console.cpp
+++ b/fpdfsdk/javascript/console.cpp
@@ -8,14 +8,11 @@
 
 #include <vector>
 
-#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_Object.h"
 #include "fpdfsdk/javascript/JS_Value.h"
-
-/* ------------------------ console ------------------------ */
+#include "fpdfsdk/javascript/cjs_context.h"
 
 BEGIN_JS_STATIC_CONST(CJS_Console)
 END_JS_STATIC_CONST()