Correcting printSummary argument names

failedWritess -> failedWrites
failedReadss -> failedReads
ByteQ now using commonQ.*Buffer/Commit*() methods

In commit 47bd384 we moved the *Buffer/Commit* methods into commonQ and
stated that PointerQ and ByteQ were now using these. This was not the
case as ByteQ still had its own implementation. This is now fixed.