favor req.file(name) over req.param(name).toUpload

[jknack]

We do provide two way of accessing file uploads today via req.param(name) or req.file(name).

We want to be more explicit so the req.param will stop working for file uploads.

req.param(name).toUpload() becomes req.file(name)

req.param(name).to(Upload.class) becomes req.file(name)

req.param(name).toList(Upload.class) becomes req.files(name)

req.param(name).toOptional(Upload.class) becomes req.ifFile(name)

Please keep in mind the req.file and req.files methods already exists.

This is a break change that affect all script routes that were using .param to retrieve file uploads. MVC routes will keep working (won't break)