Improve inheritance support in the CEF API (issue #1623).

- Support single parent inheritance in CEF API classes.
- Support non-virtual inheritance in CEF API classes.
- Support translation of CEF API sub-directories.
- Add test sub-directories for testing-only functionality that will be
  available to unit tests but not exposed via the binary distribution.
- Add unit tests for the translator tool.
- Fix parsing of template parameter types that include commas.

libcef_dll/ctocpp/write_handler_ctocpp.h

@@ -28,11 +28,9 @@ class CefWriteHandlerCToCpp
     : public CefCToCpp<CefWriteHandlerCToCpp, CefWriteHandler,
         cef_write_handler_t> {
  public:
-  explicit CefWriteHandlerCToCpp(cef_write_handler_t* str)
-      : CefCToCpp<CefWriteHandlerCToCpp, CefWriteHandler, cef_write_handler_t>(
-          str) {}
+  CefWriteHandlerCToCpp();
 
-  // CefWriteHandler methods
+  // CefWriteHandler methods.
   size_t Write(const void* ptr, size_t size, size_t n) override;
   int Seek(int64 offset, int whence) override;
   int64 Tell() override;
@@ -42,4 +40,3 @@ class CefWriteHandlerCToCpp
 
 #endif  // BUILDING_CEF_SHARED
 #endif  // CEF_LIBCEF_DLL_CTOCPP_WRITE_HANDLER_CTOCPP_H_
-