Looks up the language plugin by the inputed file type.
        
        :param      fileType | <str>
        
        :return     <XLanguage> || None

def byFileType( fileType ):
        """
        Looks up the language plugin by the inputed file type.
        
        :param      fileType | <str>
        
        :return     <XLanguage> || None
        """
        XLanguage.load()
        
        for lang in XLanguage._plugins.values():
            if ( fileType in lang.fileTypes() ):
                return lang
        return None