fastpath.Call was not incrementing pendingReadyForQueryCount when it
sent a function call. But it was being decremented when the function
call was finished and the server sent the ready for query message. This
caused pendingReadyForQueryCount to go negative. This meant that any
subsequent activity that depended on ensureConnectionReadyForQuery would
not operate correctly because the connection would be considered ready
before it had read all previous data off the wire.
fixes#403
Though this doesn't follow Go naming conventions exactly it makes names more
consistent with PostgreSQL and it is easier to read. For example, TIDOID becomes
TidOid. In addition this is one less breaking change in the move to V3.
