Parameters -D and --protocol-dump
Hi

First of all thanks for your tremendous work and for offering it to the community. Not everyone has the ability to invest thousands of dollars in mining equipment, but with cpuminer-multi everyone who has a computer is able to try and have the thrill of discovering crypto mining.

There are 2 options that I like to use with cpuminer-multi:
-D
--protocol-dump

It helps me understand the underlying protocol and what happens between my miner and the mining pool servers.

When I use these options with "skein" algorithm for example (when trying to mine DigiByte), I get this lines when I find a valid share:

```
[2017-06-04 19:17:34] DEBUG: hash <= target
Hash:   0000002d8b9db4b00486c9dd216e04550ff5468bdf6f82bc63266c46813cf52f
Target: 00000063ff9c0000000000000000000000000000000000000000000000000000
[2017-06-04 19:17:34] share diff 0.02196 (2.2x)
[2017-06-04 19:17:34] > {"method": "mining.submit", "params": ["D8En7o9BEE2PNCev837t2Df8hLFcrsYxB3", "b83c", "00000000", "59344094", "5b826200"], "id":4}
[2017-06-04 19:17:35] < {"id":4,"result":true,"error":null}
[2017-06-04 19:17:35] accepted: 61/63 (diff 0.022), 882.32 kH/s yes!
```

When I use the same parameters with "cryptonight" algorithm, I don't have the first lines of output telling me which share I submit to the pool.

Should I use another parameter to be able to see it?
Or if it isn't implemented, would it be hard to implement?

Thanks
Xavier
