ReadRequest reads the input data from a request and manage the preconditions.

SetResponseHeaders sets the response headers (for now Content-Range and Content-Location).

StripPrefix returns a new request with the URL path stripped from a prefix.

WriteBadRequest writes a BadRequest or StatusRequestEntityTooLarge status.

WriteContent writes the response and its content type.

WriteError is the more general error function, combining the previous two.

WriteServerError write a status related to a database error.

SmoothError is the generic struct for error reporting.