File upload

[dsebastien]

Points yet to clarify:

• whether the charset matters and the impact it can have on requests going through infrastructure components / request interceptors
• whether the Content-Type matters (same reaons)

We currently recommend using the application/octet-stream as Content-Type and not necessarily specifying the charset (i.e., letting it default to us-ascii. Our reasoning is that in many cases, there should not be any interpretation of the content and it should be saved as is.

Although we need to check this regarding security.