Init commit to be able to create a tor static service on the fly.

We  want to have a static Tor service created from a blob bound to
our node on cmdline

Changelog-added: persistent Tor address support
Changelog-added: allow the Tor inbound service port differ from 9735

Signed-off-by: Saibato <saibato.naga@pm.me>

Add base64 encode/decode to common

We need this to encode the blob for the tor service

Signed-off-by: Saibato <saibato.naga@pm.me>

common/base64.h

@@ -0,0 +1,10 @@
+#ifndef LIGHTNING_COMMON_BASE64_H
+#define LIGHTNING_COMMON_BASE64_H
+#include "config.h"
+#include <ccan/short_types/short_types.h>
+#include <ccan/tal/tal.h>
+
+char *b64_encode(const tal_t *ctx, const u8 *data, size_t len);
+u8 *b64_decode(const tal_t *ctx, const char *str, size_t len);
+
+#endif /* LIGHTNING_COMMON_BASE64_H */