message: doc: Update high-level addrman description
diff: @@ -104,19 +104,23 @@ public:
  * * Make sure no (localized) attacker can fill the entire table with his nodes/addresses.
  *
  * To that end:
  - * * Addresses are organized into buckets.
  - * * Addresses that have not yet been tried go into 1024 "new" buckets.
  - * * Based on the address range (/16 for IPv4) of the source of information, 64 buckets are selected at random.
  + * * Addresses are organized into buckets that can each store up to 64 entries.
  + * * Addresses to which our node has not successfully connected go into 1024 "new" buckets.
  + * * Based on the address range (/16 for IPv4) of the source of information, or if an asmap is provided,
  + * the AS it belongs to (for IPv4/IPv6), 64 buckets are selected at random.
  * * The actual bucket is chosen from one of these, based on the range in which the address itself is located.
  + * * The position in the bucket is chosen based on the full address.
  * * One single address can occur in up to 8 different buckets to increase selection chances for addresses that
  * are seen frequently. The chance for increasing this multiplicity decreases exponentially.
  - * * When adding a new address to a full bucket, a randomly chosen entry (with a bias favoring less recently seen
  - * ones) is removed from it first.
  + * * When adding a new address to an occupied position of a bucket, it will not replace the existing entry
  + * unless that address is also stored in another bucket or it doesn't meet one of several quality criteria
  + * (see IsTerrible for exact criteria).
  * * Addresses of nodes that are known to be accessible go into 256 "tried" buckets.
  * * Each address range selects at random 8 of these buckets.
  * * The actual bucket is chosen from one of these, based on the full address.
  - * * When adding a new good address to a full bucket, a randomly chosen entry (with a bias favoring less recently
  - * tried ones) is evicted from it, back to the "new" buckets.
  + * * When adding a new good address to an occupied position of a bucket, a FEELER connection to the
  + * old address is attempted. The old entry is only replaced and moved back to the "new" buckets if this
  + * attempt was unsuccessful.
  * * Bucket selection is based on cryptographic hashing, using a randomly-generated 256-bit key, which should not
  * be observable by adversaries.
  * * Several indexes are kept for high performance. Defining DEBUG_ADDRMAN will introduce frequent (and expensive)
  