Currently the `getnetworkinfo` returns something like: 

```
"localservices": "0000000000000449",
```

Manually parsing this consistently gives me a headache (see also https://github.com/sipa/bitcoin-seeder/pull/77).

It would be useful to parse this and show the right combination of `NODE_NETWORK`, `NODE_GETUTXO`, `NODE_BLOOM`, `NODE_WITNESS`, `NODE_NETWORK_LIMITED` and `NODE_COMPACT_FILTERS`. In addition the help text for `getnetworkinfo` could be expanded to mention the right BIP numbers for known flags.

There is some ad hoc parsing to populate e.g. `localrelay`, etc (?).  Their help text could also refer back to `NODE_GETUTXO`.

See also: https://en.bitcoin.it/wiki/Protocol_documentation#Network_address
"    \"subver\": \"/Satoshi:0.8.5/\",  (string) The string version\n"
            "    \"inbound\": true|false,     (boolean) Inbound (true) or Outbound (false)\n"
            "    \"addnode\": true|false,     (boolean) Whether connection was due to addnode/-connect or if it was an automatic/inbound connection\n"
            "    \"startingheight\": n,       (numeric) The starting height (block) of the peer\n"
            "    \"banscore\": n,             (numeric) The ban score\n"
            "    \"synced_headers\": n,       (numeric) The last header we have in common with this peer\n"
            "    \"synced_blocks\": n,        (numeric) The last block we have in common with this peer\n"
            "    \"inflight\": [\n"
            "       n,                        (numeric) The heights of blocks we're currently asking from this peer\n"
            "       ...\n"
            "    ],\n"
            "    \"whitelisted\": true|false, (boolean) Whether the peer is whitelisted\n"
            "    \"minfeefilter\": n,         (numeric) The minimum fee rate for transactions this peer accepts\n"
            "    \"bytessent_per_msg\": {\n"
            "       \"msg\": n,               (numeric) The total bytes sent aggregated by message type\n"
            "                               When a message type is not listed in this json object, the bytes sent are 0.\n"
            "                               Only known message types can appear as keys in the object.\n"
            "       ...\n"
            "    },\n"
            "    \"bytesrecv_per_msg\": {\n"
            "       \"msg\": n,               (numeric) The total bytes received aggregated by message type\n"
            "                               When a message type is not listed in this json object, the bytes received are 0.\n"
            "                               Only known message types can appear as keys in the object and all bytes received of unknown message types are listed under '"+NET_MESSAGE_COMMAND_OTHER+"'.\n"
            "       ...\n"
            "    }\n"
            "  }\n"
            "  ,...\n"
            "]\n"
                },
                RPCExamples{