In the log I see things like:

    2017-09-13 03:54:33 init message: Rescanning...
    2017-09-13 03:54:33 Rescanning last 68616 blocks (from block 416339)...
    2017-09-13 03:54:40 AddToWallet xxxxx  update
    2017-09-13 03:55:33 Still rescanning. At block 418849. Progress=0.549138

I would be interested to see the wallet file name on each of these log lines.

Would there be any interest in merging such a PR?
const std::vector<unsigned char>& vchCryptedSecret,
                                const CKeyMetadata &keyMeta)
{
    if (!WriteIC(std::make_pair(std::string("keymeta"), vchPubKey), keyMeta)) {
        return false;
    }
    if (!WriteIC(std::make_pair(std::string("ckey"), vchPubKey), vchCryptedSecret, false)) {
        return false;
    }
    EraseIC(std::make_pair(std::string("key"), vchPubKey));
    EraseIC(std::make_pair(std::string("wkey"), vchPubKey));
    return true;
}
bool WalletBatch::WriteMasterKey(unsigned int nID, const CMasterKey& kMasterKey)
{
    return WriteIC(std::make_pair(std::string("mkey"), nID), kMasterKey, true);
}
bool WalletBatch::WriteCScript(const uint160& hash, const CScript& redeemScript)
{
    return WriteIC(std::make_pair(std::string("cscript"), hash), redeemScript, false);
}
bool WalletBatch::WriteWatchOnly(const CScript &dest, const CKeyMetadata& keyMeta)
{
    if (!WriteIC(std::make_pair(std::string("watchmeta"), dest), keyMeta)) {
        return false;
    }
    return WriteIC(std::make_pair(std::string("watchs"), dest), '1');
}
bool WalletBatch::EraseWatchOnly(const CScript &dest)