Approved by wiz@.
Version 0.73-0
* Identify the contents of file uploads with a class "FileUploadContent"
* Don't collapse duplicate parameter values that correspond to file uploads
in MultiPartFormData objects.
* $ operator for MultiPartFormData extended to handle the case of multiple
elements for the same parameter, specifically file uploads.
* Added parameters to some functions to allow caller to specify content
of the submitted form that is usually provide via environment variables or standard
in. This facilitates debugging.
Version 0.72-2
* Deal with repeated parameters.
