Our normal import interfaces introduce keys with an effective timestamp of 0.

Importmulti introduces keys with a default effective timestamp of 'now'.

While documented it is highly surprising, especially because it contradicts the default on the rescan argument:

>     "rescan": <false>,         (boolean, optional, default: true) Stating if should rescan the blockchain after all imports

This means you can import a key and reasonably expect that it was rescanned ("I even set rescan true!") but have it not be rescanned, causing you to think the key had been unused and then you give it away and or destroy it and lose funds.

There are a number of other bugs in importmulti (mishandles pruning, needlessly forces the wallet to be unlocked when not importing private keys, etc.) which I am fixing, but I need feedback on this API issue.

Should the default become zero, with -1 special cased as 'now' or make timestamp mandatory? default it to the prune depth??

Should the result also tell us what it rescanned?
* and is thus planned to be deprecated eventually.
 *
 * Based on the source of the information, new information should be added to:
 * - `getblockchaininfo`,
 * - `getnetworkinfo` or
 * - `getwalletinfo`
 *
 * Or alternatively, create a specific query method for the information.
 **/
UniValue getinfo(const JSONRPCRequest& request)
{
    if (request.fHelp || request.params.size() != 0)
        throw runtime_error(
            "getinfo\n"
            "\nDEPRECATED. Returns an object containing various state info.\n"
            "\nResult:\n"
            "{\n"
            "  \"version\": xxxxx,           (numeric) the server version\n"
            "  \"protocolversion\": xxxxx,   (numeric) the protocol version\n"
            "  \"walletversion\": xxxxx,     (numeric) the wallet version\n"
            "  \"balance\": xxxxxxx,         (numeric) the total bitcoin balance of the wallet\n"
            "  \"blocks\": xxxxxx,           (numeric) the current number of blocks processed in the server\n"
            "  \"timeoffset\": xxxxx,        (numeric) the time offset\n"
            "  \"connections\": xxxxx,       (numeric) the number of connections\n"
            "  \"proxy\": \"host:port\",     (string, optional) the proxy used by the server\n"
            "  \"difficulty\": xxxxxx,       (numeric) the current difficulty\n"
            "  \"testnet\": true|false,      (boolean) if the server is using testnet or not\n"
            "  \"keypoololdest\": xxxxxx,    (numeric) the timestamp (seconds since Unix epoch) of the oldest pre-generated key in the key pool\n"
            "  \"keypoolsize\": xxxx,        (numeric) how many new keys are pre-generated\n"
            "  \"unlocked_until\": ttt,      (numeric) the timestamp in seconds since epoch (midnight Jan 1 1970 GMT) that the wallet is unlocked for transfers, or 0 if the wallet is locked\n"