Update ccan/structeq.

structeq() is too dangerous: if a structure has padding, it can fail
silently.

The new ccan/structeq instead provides a macro to define foo_eq(),
which does the right thing in case of padding (which none of our
structures currently have anyway).

Upgrade ccan, and use it everywhere.  Except run-peer-wire.c, which
is only testing code and can use raw memcmp(): valgrind will tell us
if padding exists.

Interestingly, we still declared short_channel_id_eq, even though
we didn't define it any more!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/invoice.c

@@ -7,7 +7,6 @@
 #include <bitcoin/base58.h>
 #include <bitcoin/script.h>
 #include <ccan/str/hex/hex.h>
-#include <ccan/structeq/structeq.h>
 #include <ccan/tal/str/str.h>
 #include <common/bech32.h>
 #include <common/bolt11.h>