All cookies are now constructed with the new function init_cookie.
Requested by Miciah Dashiel Butler Masters.
This also fixes a bug where the "Add cookie" button left cookie->path == NULL,
causing a crash later when deciding whether to send the cookie to the server.
src/cookies/dialogs.c (set_server): Set up a struct cookie and pass it
to accept_cookie, instead of calling set_cookie which might ask the user
to confirm. (This change also removes a dubious use of struct uri.)
src/cookies/cookies.c (get_cookie_server): No longer static.
src/cookies/cookies.h (get_cookie_server): Declare.
