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>

wire/wire.h

@@ -9,12 +9,15 @@
 #include <bitcoin/signature.h>
 #include <ccan/crypto/sha256/sha256.h>
 #include <ccan/short_types/short_types.h>
+#include <ccan/structeq/structeq.h>
 #include <secp256k1_recovery.h>
 #include <stdlib.h>
 
 struct channel_id {
 	u8 id[32];
 };
+/* Define channel_id_eq (no padding) */
+STRUCTEQ_DEF(channel_id, 0, id);
 
 struct bitcoin_blkid;
 struct bitcoin_txid;