Message headers are converted unexpectedly to lowe-case in a Camel service.

For instance, suppose the header "CamelFileName" is set in a Camel route like the following:

        from("switchyard://FileService")
                .setHeader(Exchange.FILE_NAME, constant("out.txt"))
                .to("switchyard://FTPOut");

it's then converted automatically to lower-case "camelfilename" when it reaches the context mapper.

It is a problem because we need to specify the 'includes' of the context mapper as "camelfilename" instead of "CamelFileName". It's counter-intuitive and thus should be a bug.