Really, we should only #define this in one file, not both here and in
connect.c!

add 'headers=' in client formpost

Reminder for the future: when we're using malloc() we MUST include <stdlib.h>
as otherwise 64bit archs go bananas.

Bug report #517687

was an extra CRLF added to the post data

content-type header, it was used for each part and thus without this it
failed MISERABLY. *smacks forhead*

accordingly