bitcoin/bitcoin — pull request #1652 by jgarzik (2012-08-02 18:04:05+00:00)
Title: Report 'neverseen' TXs: the number of TXs in block, but not memory pool

This statistic is only reported when a new block appends onto the
strongest chain.

Tested by comparing bitcoind new-block results with pynode, which performs a similar calculation.