support go1.8 database/sql changes

[kardianos]

I'm unsure if this is an experiment or production ready (maybe both?).

Go1.8 support new interfaces detailed here: https://docs.google.com/document/d/1F778e7ZSNiSmbju3jsEWzShcb8lIO4kDyfKDNm4PNd8/edit

Of note, how does the protocol X handle cancelations? Is it part of the protocol or do you still have to run a new KILL query?