I'm hoping to enhance the HTTP Request sampler, by adding functionality to
support multipart/form-data http post request with only parameters, if the user
selects to do that. And also add support for uploading several files in one HTTP
request.

I feel that in order to be able to add more options for the user for HTTP
Request, the GUI needs to be restructured. I think it should be easy and simple
for normal users, who I guess only are doing "HTTP GET" requests. But it must
also have room for options for more advanced users, i.e. doing HTTP Post with
many files.

I suggest to have the upper part of the GUI as it is now, but to change the
lower part to use a tabbed pane layout. I suggest tabs such as "options",
"parameters", "file upload".

I have looked at the code, and will attach a suggested patch, just a prototype,
shortly. Mainly, I want your opinion if it makes sense to restructure the GUI,
and secondly, if it is possible to restructure the GUI and the code like I have
started on doing, and still being able to read old test plans and populate the
GUI correctly.

I think the "HTTP Request Defaults" GUI can stay as it is, for now.

If you don't like my suggestion for restructuring the GUI, how do you think we
can add more options to this already quite crowded GUI ?