Use more efficient ID encoding for adbd *breaking all old DBs*
Use more efficient ID encoding for adbd *breaking all old DBs*

Like merkle_tree_bdb, directly use big-endian encoding of raw,
padded out to 20 bytes for proper sorting.

weidezhang/dht,sit/dht,sit/dht,weidezhang/dht,weidezhang/dht,sit/dht,weidezhang/dht,weidezhang/dht,sit/dht,sit/dht