CellScanner and WALWEntries need to be kept in sync

This is a small tweak that makes SepConsumerIT test pass in HBase 0.95 profile and actually fixes the very core of SepConsumer functionality (so it is kind of important to have this fix ;-))

It seems to do the right thing, but I'd love to hear suggestions for how to do it more efficiently. I'll ask a few HBase folks for advice. Stay tuned.

Thanks,
Roman.