Fixes #212 Declare the purpose of the Less, Len, Swap methods so that readers can see why they are defined. Raised by an auditor in their report, as it looked like a security concern but actually sort.Interface requires those methods implemented.
* Add info to Response[CheckTx/DeliverTx/Query] * Remove code and log from Response[SetOption/Commit]
KVPair is {[]byte,[]byte}
* Use gogoproto's nullable=false where appropriate.
