This turns the data-functions into the only functions "allowed"
to send body-data (called with http_send_body()). The previous (hacky)
approach of doing this in http_send_header() is not only out of place,
it's an easy source of bugs given, for instance, the sending of body
data is not expected with HEAD-requests.
Given html_escape() is now only used in data.c, we move it there from
util.c and make it a static method again.
Signed-off-by: Laslo Hunhold <dev@frign.de>
The methods in data.h only deal with the actual response data, not
the request handling itself, which has been formalized a bit more
in http.h. To avoid confusion, we rename it to data.h.
Signed-off-by: Laslo Hunhold <dev@frign.de>
