Replace nearly all XXX0vv comments with smarter ones

So, back long ago, XXX012 meant, "before Tor 0.1.2 is released, we
had better revisit this comment and fix it!"

But we have a huge pile of such comments accumulated for a large
number of released versions!  Not cool.

So, here's what I tried to do:

  * 0.2.9 and 0.2.8 are retained, since those are not yet released.

  * XXX+ or XXX++ or XXX++++ or whatever means, "This one looks
    quite important!"

  * The others, after one-by-one examination, are downgraded to
    plain old XXX.  Which doesn't mean they aren't a problem -- just
    that they cannot possibly be a release-blocking problem.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/or/rendclient.c b/src/or/rendclient.c
index c119d86adf..7e92dce6d4 100644
--- a/src/or/rendclient.c
+++ b/src/or/rendclient.c
@@ -510,7 +510,7 @@ lookup_last_hid_serv_request(routerstatus_t *hs_dir,
   tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s",
                hsdir_id_base32,
                desc_id_base32);
-  /* XXX023 tor_assert(strlen(hsdir_desc_comb_id) ==
+  /* XXX++?? tor_assert(strlen(hsdir_desc_comb_id) ==
                        LAST_HID_SERV_REQUEST_KEY_LEN); */
   if (set) {
     time_t *oldptr;
@@ -572,7 +572,7 @@ purge_hid_serv_from_last_hid_serv_requests(const char *desc_id)
     const char *key;
     void *val;
     strmap_iter_get(iter, &key, &val);
-    /* XXX023 tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */
+    /* XXX++?? tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */
     if (tor_memeq(key + LAST_HID_SERV_REQUEST_KEY_LEN -
                   REND_DESC_ID_V2_LEN_BASE32,
                   desc_id_base32,
@@ -1099,7 +1099,7 @@ rend_client_rendezvous_acked(origin_circuit_t *circ, const uint8_t *request,
    * service and never reply to the client's rend requests */
   pathbias_mark_use_success(circ);
 
-  /* XXXX This is a pretty brute-force approach. It'd be better to
+  /* XXXX++ This is a pretty brute-force approach. It'd be better to
    * attach only the connections that are waiting on this circuit, rather
    * than trying to attach them all. See comments bug 743. */
   /* If we already have the introduction circuit built, make sure we send