src/translatordecoder.h removed, winbuild/Doxygen.vcproj updated

When running... doxygen/doc>py translator.py
This script should be updated. All translators do use UTF-8
internally.  The TranslatorDecoder adapter should be removed
from the code and its usage should not be checked any more.

(I do not believe I ever had so much time to add a check like this
to the translator.py :)

winbuild/Doxygen.vcproj

@@ -4181,10 +4181,6 @@
 				RelativePath="..\src\translator_za.h"
 				>
 			</File>
-			<File
-				RelativePath="..\src\translatordecoder.h"
-				>
-			</File>
 			<File
 				RelativePath="..\src\unistd.h"
 				>