This reverts commit 3b4701b240f55b4e97edee7fdc13fec35a76fc5a.

This reverts commit 647d32a29978579f88baa7c06c207e6a8d6a0d3e, reversing
changes made to 22063af06536671b680fa9bc84b4626192c106cc.

JavaScript-free uploading was introduced in Pomf 2.0 as a misfeature. It
increases complexity of the API code base and duplicates some code.

This was obviously a misled approach to Pomf development. The
recommended approach to solving this issue is using the upload API with
external tools.

ewhal fell off.

Cc: Eliot Whalan <ewhal@pantsu.cat>

I have a belief that Swig banners are a Grunt only thing, and they don't
really integrate very well into Swig anyway. It's kind of a hack, and a
bad one because we don't need it anymore.

By deprecating Swig banners, we should have easier time replacing
Grunt/npm with Make in a future release.

Reviewed-by: Eliot Whalan <ewhal@pantsu.cat>

The JavaScript-free uploader doesn't care about browser features too
much, specifically about window.FormData. That API is for JavaScript.

Because there also isn't any JavaScript to execute, this template never
gets called. It's dead HTML, so remove it.

The <header> element represents a group of introductory or navigational
aids. It is semantically incorrect to use it with only one element
inside.

The <header> element was introduced in commit 87014fa08f. That commit
describes the correct usage of <header> element with multiple elements
inside <header>.

This bug was introduced in commit fd566d3d7f.